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Astronomy & Astrophysics manuscript no. vla˙v5 c
ESO 2018
January 12, 2018
Radio-emitting narrow-line Seyfert 1
galaxies in the JVLA perspective
M. Berton1,2?, E. Congiu1,2, E. J¨
arvel¨
a3,4, R. Antonucci5, P. Kharb6, M. L. Lister7, A. Tarchi8,
A. Caccianiga2, S. Chen1,9,10, L. Foschini2, A. L¨
ahteenm¨
aki3,4,11, J. L. Richards7,
S. Ciroi1,12, V. Cracco1, M. Frezzato1, G. La Mura1, and P. Rafanelli1
1Dipartimento di Fisica e Astronomia ”G. Galilei”, Universit`
a di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy;
2INAF - Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (LC), Italy;
3Aalto University Mets¨
ahovi Radio Observatory, Mets¨
ahovintie 114, FIN-02540 Kylm¨
al¨
a, Finland;
4Aalto University Department of Electronics and Nanoengineering, P.O. Box 15500, FI-00076 AALTO, Finland;
5Department of Physics, University of California, Santa Barbara, CA 93106-9530, USA;
6National Centre for Radio Astrophysics - Tata Institute of Fundamental Research, Post Bag 3, Ganeshkhind, Pune 411007, India;
7Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907, USA;
8INAF - Osservatorio Astronomico di Cagliari, Via della Scienza 5, 09047, Selargius (CA), Italy;
9INFN - Sezione di Padova, Via Marzolo 8, 35131, Padova;
10 Center for Astrophysics, Guangzhou University, Guangzhou 510006, China;
11 Tartu Observatory, Observatooriumi 1, 61602 T˜
oravere, Estonia;
12 INAF - Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy.
Preprint online version: January 12, 2018
ABSTRACT
We report the first results of a survey on 74 narrow-line Seyfert 1 galaxies (NLS1s) carried out in 2015 with the Karl J. Jansky
Very Large Array (JVLA) at 5 GHz in A-configuration. So far, this is the largest survey aimed to image the radio continuum of
NLS1s. We produced radio maps in order to compare the general properties of three different samples of objects: radio-quiet NLS1s
(RQNLS1s), steep-spectrum radio-loud NLS1s (S-NLS1s), and flat-spectrum radio-loud NLS1s (F-NLS1s). We find that the three
classes correspond to different radio morphologies, with F-NLS1s being more compact, and RQNLS1s often showing diffuse emission
on kpc scales. We also find that F-NLS1s might be low-luminosity and possibly young blazars, and that S-NLS1s are part of the parent
population of F-NLS1s. Dedicated studies to RQNLS1s are needed in order to fully understand their role in the unification pictures.
Key words. galaxies: active; galaxies: jets; quasars: supermassive black holes; galaxies: Seyfert
1. Introduction
Narrow-line Seyfert 1 galaxies (NLS1s) are active galactic nu-
clei (AGN) characterized by optical emission spectra similar
to those in ordinary Seyfert 1 galaxies (Sy1s), with ratio [O
III]/Hβ < 3 and strong Fe II multiplets, but unlike Sy1s they have
narrower permitted lines (Osterbrock & Pogge 1985; Goodrich
1989). These properties indicate that the high-density broad-line
region (BLR) in NLS1s is visible, unlike in Seyfert 2s, but con-
tains material moving much more slowly than in ordinary Sy1s.
This, assuming a similar BLR size, implies that the central black
hole masses should be smaller than in other Sy1s of similar lumi-
nosity. Indeed those measured in NLS1s range from 105-108M,
typically smaller than the 107-109Mfound in regular Sy1s, and
the 108-1010 typical of blazars (Grupe 2000; J¨
arvel¨
a et al. 2015;
Cracco et al. 2016). NLS1s are also characterized by large ac-
cretion rates relative to the Eddington limit, often approaching
that limit (Boroson & Green 1992; Sulentic et al. 2000). Many
of their properties suggest they may represent young AGN in an
early stage of evolution (e.g. Mathur 2000). NLS1s are typically
hosted by disk galaxies, whereas blazars and radio galaxies are
normally found in ellipticals (Crenshaw et al. 2003; Orban de
Xivry et al. 2011).
?marco.berton@unipd.it
However, a disk-like BLR and a low inclination could also
mimic the effect of a low-mass black hole. In this scenario,
the narrowness of permitted lines would be due to the lack of
Doppler broadening in a disk-BLR observed pole-on (Decarli
et al. 2008). Although this model is somewhat in contradic-
tion with the current understanding of the physics behind the
blazar sequence (Ghisellini et al. 1998; Foschini 2017), the low-
mass/low-inclination degeneracy is one of the most debated is-
sues about NLS1s nature.
Most NLS1s are radio-quiet1, but not radio-silent (Giroletti
& Panessa 2009; Doi et al. 2013; L¨
ahteenm¨
aki et al. 2017).
About 7% are radio-loud, a lower incidence than among quasars
(Komossa et al. 2006), however this fraction is strongly depen-
dent on the redshift, since it appears to be lower (3.5%) in the
nearby Universe (Cracco et al. 2016) and to be dependent on the
large-scale environment (J¨
arvel¨
a et al. 2017). The γ-ray emission
detected by the Fermi Large Area Telescope (LAT) in 12 radio-
loud NLS1s (Foschini et al. 2015; Liao et al. 2015; Yao et al.
2015; D’Ammando et al. 2015; Berton et al. 2017) confirmed
the presence of a relativistic jet. Indeed, images from Very Long
1According to Kellermann et al. (1989), radio-loudness is defined as
the flux ratio RL =S5GHz /SB−band. If RL >10, the source is radio-loud,
conversely it is radio-quiet. We define sources without radio detection
as radio-silent.
1
arXiv:1801.03519v1 [astro-ph.GA] 10 Jan 2018
M. Berton et al.: NLS1s with JVLA
Baseline Array (VLBA) observations of several NLS1s show
blazar-like parsec-scale radio jets, with high brightness temper-
ature, flat or inverted radio spectra, fast variability, and a sig-
nificant degree of polarization (Abdo et al. 2009a; Ikejiri et al.
2011; Lister et al. 2013; Gu et al. 2015). In some cases, ap-
parent superluminal motion is also present (Lister et al. 2016).
The production of relativistic jets among a population of AGN
with small black hole masses and large Eddington accretion rates
runs counter to the general trend of stronger jets in AGN with
larger black holes and lower accretion rates (Laor 2000; Boroson
2002; B¨
ottcher & Dermer 2002; Marscher 2009). Furthermore,
by analogy with stellar-mass black holes, AGN in high accretion
states would be expected to correspond to the high/soft state,
where jets are quenched (e.g. Maccarone et al. 2003). NLS1s
thus present a puzzle with respect to the current understanding
of jet production mechanisms.
It is not yet clear how to include radio-loud NLS1s in the
prevailing orientation-driven AGN unification model (Antonucci
1993; Urry & Padovani 1995). In this picture, the powerful
blazars result when members of a jetted parent population −the
radio galaxies −happen to be oriented with the jet nearly along
our line of sight. In this preferred orientation, emission from
the jet is relativistically beamed toward the observer, greatly en-
hancing its apparent luminosity. The presence of beamed emis-
sion in radio-loud NLS1s (Abdo et al. 2009b) suggests that these
sources may be the low-mass and low-luminosity analogs of flat-
spectrum radio quasars (FSRQ, Foschini et al. 2015; Berton et al.
2016a). If this is correct, a corresponding unbeamed parent pop-
ulation must exist. This population of misaligned NLS1s must be
rather large: assuming a negligible aperture of the jet cone, ∼2Γ2
members of the parent population should be observable, where
Γis the typical jet bulk Lorentz factor. For reasonable values Γ∼
10 (Abdo et al. 2009b), the parent population should outnumber
the radio-loud NLS1 population by a factor of about 200. The
nature of this parent population is still unclear. Steep-spectrum2
radio-loud NLS1s (S-NLS1s), disk-hosted radio galaxies and
compact steep-spectrum sources (CSS)3appear to be good can-
didates (Berton et al. 2015, 2016a, 2017), but even among radio-
quiet sources some parent objects could be hidden (Tarchi et al.
2011; Berton et al. 2016b; L¨
ahteenm¨
aki et al. 2017).
Several studies have found NLS1s to be predominantly com-
pact on kiloparsec scales; extended morphologies have been re-
ported in some cases (Gliozzi et al. 2010; Doi et al. 2012, 2015;
Richards & Lister 2015; Gu et al. 2015; Caccianiga et al. 2017;
Congiu et al. 2017a). However, the majority of observations on
this scale come from the FIRST survey (Becker et al. 1995), in
which only sources larger than 200 are resolved to the 500 synthe-
sized beam (White et al. 1997). A wide gap between the 200 scale
and the scales of a few milliarcsecond explored by Very Large
Baseline Interferometry (VLBI) observations remains largely
unexplored.
In order to fill this gap, we observed a large sample of 74
NLS1s, both radio-loud and radio-quiet, with the Karl J. Jansky
Very Large Array (JVLA) at 5 GHz in A-configuration. For
many of these sources (∼40), this is the first observation ever
performed at this frequency, and will allow to get a spectral in-
dex measurement, which is essential to distinguish between flat-
and steep-spectrum objects. The aim of this study is also to find,
thanks to the enhanced sensitivity of the JVLA, new objects with
2Typically evaluated with two frequencies around L band.
3CSS are here defined as jetted radio-loud sources with compact
morphology and steep radio spectrum (e.g. Kunert-Bajraszewska et al.
2010).
kpc-scale jets which can contribute to increase the number of
parent sources.
In this paper we will present the main results of this survey,
focusing on the general properties of these sources. In Sect. 2 we
will describe the sample, in Sect. 3 we will describe the observa-
tions and the data analysis, in Sect. 4 we will present our results,
in Sect. 5 we will discuss them, and in Sect. 6 we will provide
a brief summary of this work. Throughout this paper, we adopt
a standard ΛCDM cosmology, with a Hubble constant H0=70
km s−1Mpc−1, and ΩΛ=0.73 (Komatsu et al. 2011). Spectral
indexes are specified with flux density Sν∝ν−αat frequency ν.
2. Sources selection
Our sample is mainly based on the samples of FIRST detected
sources (flux density limit ∼1 mJy at 1.4 GHz) analyzed by
Foschini et al. (2015) and Berton et al. (2015). From those
samples, we excluded sources already observed in detail at 5
GHz (e.g. PMN J0948+0022, observed repeatedly), and also
three already known to have extended emission (Richards &
Lister 2015). We instead included in our sample a few more
objects found in the literature that were claimed to harbor a
relativistic jet. These new sources were Mrk 335 (e.g. Gallo
et al. 2013), IRAS 03450+0055 (Tarchi et al. 2011), IRAS
06269-0543 (Moran 2000), B2 1111+32 (Komossa et al. 2006),
SBS 1315+604 (Wadadekar 2004), and Ark 564 (Moran 2000).
Among these, only IRAS 03450+0055 was included in the
FIRST. The others were instead detected in the NVSS sur-
vey (Condon et al. 1998). Five more sources were also orig-
inally observed, but we did not include them in the sample
we will analyze in the following for different reasons. SDSS
J164200.55+533950.6 and SBS 0748+499 were classified in the
literature as NLS1s, but after a more careful analysis of their op-
tical spectra we concluded that they do not belong to this class:
they are in fact a regular Seyfert 1 (Puchnarewicz et al. 1992)
and an intermediate-type Seyfert, respectively. Mrk 739W was
observed regularly, but resulted in a non-detection. Finally, both
SDSS J143221.43+322318.5 and RX J1016.7+4210 were not
correctly pointed. All of our sources have a FWHM(Hβ)<2000
km s−1, a ratio [O III]/Hβ < 3, and Fe II multiplets in their op-
tical spectrum. The total number of sources is then 74, listed in
Tab. 1.
3. Data analysis
The data we present in this paper were obtained in the A config-
uration of the JVLA in several sessions between 2015 July and
September. The observations were carried out at 5 GHz with a
bandwidth of 2 GHz, for a total observing time of approximately
24 hours. The project code is 15A-283 (P.I. Richards). The list
of sources with their main parameters and the exposure time for
each object is reported in Tab. A.1.
We reduced and analyzed the data using the Common
Astronomy Software Applications (CASA) version 4.7.2 and the
standard Expanded VLA (EVLA) data reduction pipeline ver-
sion 4.7.2. For each dataset, a different flux calibrator was used.
We point out here that one of the main calibrators, 3C 286, is a S-
NLS1 partially resolved on VLA scales (An et al. 2017; Berton
et al. 2017).
We split offthe measurement set of each object from the
main datasets, averaging over the 64 channels of each one of the
16 spectral windows (centered on 4.271, 4.399, 4.527, 4.655,
4.783, 4.911, 5.039, 5.167, 5.301, 5.429, 5.557, 5.685, 5.813,
2
M. Berton et al.: NLS1s with JVLA
Table 1. The sample.
Short name NED Alias R.A. Dec. z Scale Old New Map Type
J0006+2012 Mrk 335 00 06 19.50 +20 12 10.0 0.026 0.523 Q Q Fig. C.1 C
J0100−0200 FBQS J0100−0200 01 00 32.22 −02 00 46.3 0.227 3.638 F S Fig. C.1 C
J0146−0040 2MASX J01464481−0040426 01 46 44.80 −00 40 43.0 0.083 1.561 Q Q Fig. C.2 C
J0347+0105 IRAS 03450+0055 03 47 40.20 +01 05 14.0 0.031 0.620 Q Q Fig. C.2 E
J0629−0545 IRAS 06269−0543 06 29 24.70 −05 45 30.0 0.117 2.116 S F Fig. C.3 I
J0632+6340 UGC 3478 06 32 47.20 +63 40 25.0 0.013 0.266 Q Q Fig. C.3 E
J0706+3901 FBQS J0706+3901 07 06 25.15 +39 01 51.6 0.086 1.612 F S Fig. C.4 I
J0713+3820 FBQS J0713+3820 07 13 40.29 +38 20 40.1 0.123 2.210 F S Fig. C.4 E
J0744+5149 NVSS J074402+514917 07 44 02.24 +51 49 17.5 0.460 5.831 F S Fig. C.5 C
J0752+2617 FBQS J0752+2617 07 52 45.60 +26 17 36.0 0.082 1.544 Q Q Fig. C.5 C
J0758+3920 FBQS J075800.0+392029 07 58 00.05 +39 20 29.1 0.096 1.779 S S Fig. C.6 E
J0804+3853 FBQS J0804+3853 08 04 09.24 +38 53 48.7 0.212 3.453 F S Fig. C.6 E
J0806+7248 RGB J0806+728 08 06 38.96 +72 48 20.4 0.098 1.812 S F Fig. C.7 I
J0814+5609 SDSS J081432.11+560956.6 08 14 32.13 +56 09 56.6 0.510 6.168 F F Fig. C.7 I
J0849+5108* SBS 0846+513 08 49 57.99 +51 08 28.8 0.585 6.606 G F Fig. C.8 C
J0850+4626 SDSS J085001.17+462600.5 08 50 01.17 +46 26 00.5 0.524 6.256 S F Fig. C.8 C
J0902+0443 SDSS J090227.16+044309.5 09 02 27.15 +04 43 09.4 0.533 6.311 F F Fig. C.9 C
J0913+3658 RX J0913.2+3658 09 13 13.70 +36 58 17.0 0.107 1.958 Q Q Fig. C.9 I
J0925+5217 Mrk 110 09 25 12.90 +52 17 11.0 0.035 0.697 Q Q Fig. C.10 E
J0926+1244 Mrk 705 09 26 03.30 +12 44 04.0 0.029 0.581 Q Q Fig. C.10 I
J0937+3615 SDSS J093703.03+361537.2 09 37 03.01 +36 15 37.3 0.180 3.035 F S Fig. C.11 E
J0945+1915 SDSS J094529.23+191548.8 09 45 29.21 +19 15 48.9 0.284 4.287 F S Fig. C.11 C
J0948+5029 Mrk 124 09 48 42.60 +50 29 31.0 0.056 1.087 Q Q Fig. C.12 C
J0952−0136 Mrk 1239 09 52 19.10 −01 36 43.0 0.020 0.405 Q Q Fig. C.12 I
J0957+2433 RX J0957.1+2433 09 57 07.20 +24 33 16.0 0.082 1.544 Q Q Fig. C.13 C
J1031+4234 SDSS J103123.73+423439.3 10 31 23.73 +42 34 39.4 0.377 5.180 F S Fig. C.13 C
J1034+3938 KUG 1031+398 10 34 38.60 +39 38 28.0 0.042 0.829 S F Fig. C.14 I
J1037+0036 SDSS J103727.45+003635.6 10 37 27.45 +00 36 35.8 0.595 6.659 F F Fig. C.14 C
J1038+4227 SDSS J103859.58+422742.3 10 38 59.59 +42 27 42.0 0.220 3.552 F S Fig. C.15 E
J1047+4725 SDSS J104732.68+472532.0 10 47 32.65 +47 25 32.2 0.799 7.505 F F Fig. C.15 E
J1048+2222 SDSS J104816.57+222238.9 10 48 16.56 +22 22 40.1 0.330 4.752 F S Fig. C.16 I
J1102+2239* SDSS J110223.38+223920.7 11 02 23.36 +22 39 20.7 0.453 5.781 G S Fig. C.16 I
J1110+3653 SDSS J111005.03+365336.3 11 10 05.03 +36 53 36.1 0.629 6.830 F F Fig. C.17 I
J1114+3241 B2 1111+32 11 14 38.89 +32 41 33.4 0.189 3.156 S F Fig. C.17 C
J1121+5351 SBS 1118+541 11 21 08.60 +53 51 21.0 0.103 1.893 Q Q Fig. C.18 I
J1138+3653 SDSS J113824.54+365327.1 11 38 24.54 +36 53 27.1 0.356 4.994 F F Fig. C.18 I
J1146+3236 SDSS J114654.28+323652.3 11 46 54.30 +32 36 52.2 0.465 5.867 F F Fig. C.19 C
J1159+2838 SDSS J115917.32+283814.5 11 59 17.31 +28 38 14.8 0.210 3.427 F S Fig. C.19 I
J1203+4431 NGC 4051 12 03 09.60 +44 31 53.0 0.002 0.041 Q Q Fig. C.20 E
J1209+3217 RX J1209.7+3217 12 09 45.20 +32 17 01.0 0.144 2.527 Q Q Fig. C.20 I
J1215+5442 SBS 1213+549A 12 15 49.40 +54 42 24.0 0.150 2.614 Q Q Fig. C.21 I
J1218+2948 Mrk 766 12 18 26.50 +29 48 45.8 0.013 0.266 Q Q Fig. C.21 E
J1227+3214 SDSS J122749.14+321458.9 12 27 49.15 +32 14 59.0 0.136 2.408 F F Fig. C.22 I
J1238+3942 SDSS J123852.12+394227.8 12 27 49.15 +39 42 27.6 0.622 6.796 F F Fig. C.22 C
J1242+3317 WAS 61 12 42 10.60 +33 17 03.0 0.044 0.866 Q Q Fig. C.23 E
J1246+0222 PG 1244+026 12 46 35.20 +02 22 09.0 0.048 0.941 Q Q Fig. C.23 E
J1246+0238* SDSS J124634.65+023809.0 12 46 34.68 +02 38 09.0 0.367 5.092 G F Fig. C.24 C
J1302+1624 Mrk 783 13 02 58.80 +16 24 27.0 0.067 1.284 S S Fig. C.24 E
J1305+5116* SDSS J130522.74+511640.2 13 05 22.75 +51 16 40.3 0.788 7.469 S F Fig. C.25 E
J1317+6010 SBS 1315+604 13 17 50.30 +60 10 41.0 0.137 2.423 Q Q Fig. C.25 E
J1333+4141 SDSS J133345.47+414127.7 13 33 45.47 +41 41 28.2 0.225 3.614 F S Fig. C.26 C
J1337+2423 IRAS 13349+2438 13 37 18.70 +24 23 03.0 0.108 1.974 Q Q Fig. C.26 I
J1346+3121 SDSS J134634.97+312133.7 13 46 35.07 +31 21 33.9 0.246 3.864 F F Fig. C.27 C
J1348+2622 SDSS J134834.28+262205.9 13 48 34.25 +26 22 05.9 0.917 7.832 F S Fig. C.27 I
J1355+5612 SBS 1353+564 13 55 16.50 +56 12 45.0 0.122 2.194 Q Q Fig. C.28 C
J1358+2658 SDSS J135845.38+265808.4 13 58 45.40 +26 58 08.3 0.331 4.762 F S Fig. C.28 I
J1402+2159 RX J1402.5+2159 14 02 34.40 +21 59 52.0 0.066 1.266 Q Q Fig. C.29 I
J1421+2824 SDSS J142114.05+282452.8 14 21 14.07 +28 24 52.2 0.539 6.347 F F Fig. C.29 C
J1443+4725* SDSS J144318.56+472556.7 14 43 18.56 +47 25 56.7 0.705 7.166 S F Fig. C.30 C
J1505+0326* SDSS J150506.47+032630.8 15 05 06.47 +03 26 30.8 0.408 5.438 G F Fig. C.30 C
J1536+5433 Mrk 486 15 36 38.30 +54 33 33.0 0.039 0.772 Q Q Fig. C.31 I
J1537+4942 SDSS J153732.61+494247.5 15 37 32.60 +49 42 48.0 0.280 4.244 Q Q Fig. C.31 C
J1548+3511 SDSS J154817.92+351128.0 15 48 17.92 +35 11 28.4 0.479 5.964 F F Fig. C.32 C
J1555+1911 Mrk 291 15 55 07.90 +19 11 33.0 0.035 0.697 Q Q Fig. C.32 E
J1559+3501 Mrk 493 15 59 09.60 +35 01 47.0 0.031 0.620 Q Q Fig. C.33 E
J1612+4219 SDSS J161259.83+421940.3 16 12 59.83 +42 19 40.0 0.233 3.710 F F Fig. C.33 E
J1629+4007 SDSS J162901.30+400759.9 16 29 01.31 +40 07 59.6 0.272 4.157 F F Fig. C.34 C
J1633+4718 SDSS J163323.58+471858.9 16 33 23.58 +47 18 59.0 0.116 2.101 F F Fig. C.34 I
J1634+4809 SDSS J163401.94+480940.2 16 34 01.94 +48 09 40.1 0.495 6.071 F F Fig. C.35 C
J1703+4540 SDSS J170330.38+454047.1 17 03 30.38 +45 40 47.2 0.060 1.159 S F Fig. C.35 I
J1709+2348 SDSS J170907.80+234837.7 17 09 07.82 +23 48 38.2 0.254 3.956 F S Fig. C.36 C
J1713+3523 FBQS J1713+3523 17 13 04.48 +35 23 33.4 0.083 1.561 S S Fig. C.36 I
J2242+2943 Ark 564 22 42 39.30 +29 43 31.0 0.025 0.504 Q Q Fig. C.37 E
J2314+2243 RX J2314.9+2243 23 14 55.70 +22 43 25.0 0.169 2.884 S F Fig. C.37 I
Notes. Columns: (1) short name; (2) NED alias; (3) right ascension (J2000); (4) declination (J2000); (5) redshift; (6) scale (kpc arcsec−1); (7)
old classification: Q indicates radio-quiet, S is steep-spectrum radio-loud, F is flat-spectrum radio-loud; G is gamma-ray emitter; (8) updated
classification (G sources are included in the F sample); (9) figure showing the radio map; (10) morphology type: C indicates compact, I is
intermediate morphology, and E indicates the presence of diffuse emission. The asterisk indicates that the source has been detected at γ-rays by
the Fermi satellite.
3
M. Berton et al.: NLS1s with JVLA
Fig. 1. Spectral index between 1.4 and 5 GHz vs in-band spectral index at 5 GHz. From the left, F sample, Q sample, and S sample.
The colors indicate the classification, from left to right: black is for F objects, blue for the Q sample, and red for the S sources.
Circles indicates compact sources, squares intermediate sources and triangles extended sources. The dashed black line indicates the
1:1 ratio, the dashed-dotted red lines separate the region of flat-spectrum sources (α < 0.5) from that of steep-spectrum objects.
5.941, 6.069, 6.197 GHz) and over 10 seconds of exposure time.
To produce the maps, we used a pixel size of 0.05 arcsec. First
we analyzed a region of 8192×8192 px centered on the source
coordinates that covers most of the primary beam, checking for
the presence of nearby sources to avoid contamination from their
sidelobes. When nearby sources were present we modelled them
along with the main target. In a few cases, the non perfect mod-
eling of nearby sources severely affected the quality of the maps
(e.g. J1612+4219, affected by CRATES J1613+4223). Each re-
gion was cleaned using all the available spectral windows and
a natural weighting to create a first tentative image. In three
bright sources (J0849+5108, J1505+0326, J1047+4725), we ap-
plied a uniform weighting to reduce the sidelobes contribution.
In J1209+3217, instead, we applied a Briggs weighting interme-
diate between natural and uniform, to reduce the sidelobe ampli-
tudes without an excessive loss of dynamic range.
After the first cleaning, when the noise level was close to the
predicted thermal noise of ∼10 µJy beam−1, we did not proceed
any further. Conversely, for higher noise levels, we proceeded
with iterative cycles of phase only self-calibration on the visi-
bilities, in order to improve the dynamic range. When possible,
we applied to the visibilities a final self-calibration both in am-
plitude and phase. For each source we modelled the beam with
a Gaussian in the image plane and we deconvolved it from the
core. It was therefore possible to recover the core deconvolved
size, its position angle, the peak and the integrated (i.e. total) flux
density. When the source had multiple components, to measure
the total extension of the emission we applied to the visibilities
a Gaussian taper with a radius of 120 kλ, and we derived the
total flux of the object. We then derived the integrated and peak
luminosity following as usual L=4πd2
LF(1 +z)1−αν, where αν
is the spectral index associated to each flux and dLis the lumi-
nosity distance. In particular, we estimated the in-band spectral
index measuring the flux of the source in two bands obtained by
splitting the data in two separate frequency windows, centered
on 4.7 and 5.7 GHz respectively. To minimize the difference in
beam size as a function of frequency, in each source we selected
only the uv range common to all spectral windows. Finally, to es-
timate the diffuse luminosity, we calculated the extended flux by
subtracting the peak flux from the total flux, and we converted it
in luminosity assuming a spectral index of αν=−1. A dedicated
analysis of the extended sources and their tapered images will
be presented in a subsequent paper. The errors associated with
each measurement are those produced by CASA in all cases but
Fig. 2. The redshift distribution of the four subsamples and of
the whole sample. From top to bottom, F, Q, S subsamples, and
the whole sample.
the extended emission, where it was estimated as the product of
the rms per beam as measured in an empty region of the image
times the square root of the object size expressed in beams.
We also measured the brightness temperature Tbfor each
source, which was calculated following Doi et al. (2013) and
using
Tb=1.8×109(1 +z)Sν,p
ν2θma jθmin
[K] ,(1)
where Sν,pis the peak flux density in mJy beam−1,νis the ob-
serving frequency, and θma j,θmin are the major and minor axis
of the source core in milliarcsec, deconvolved from beam. When
the latter measurement was not available, we used as beam size
the average deconvolved beam size calculated within each sam-
ple.
4. Spectral indexes and samples
During the observations, our sample was initially divided in 4
subsamples, according to their radio and γ-ray properties, that is
γ-ray emitters, flat-spectrum radio-loud, steep-spectrum radio-
4
M. Berton et al.: NLS1s with JVLA
loud, and radio-quiet. However, this classification has to be up-
dated in the light of the results of the present survey. We decided
to regroup the sources as a function of their radio properties only,
regardless of the γ-ray emission. At the time of the original sam-
ple creation, indeed, only four of our sources were detected at
γ-rays (marked with G in Col. 7 of Tab. 1), while to date at least
two more have been found (Liao et al. 2015). Furthermore, since
radio emission can change in time because of source variability,
we tried to avoid a classification based on non-simultaneous ob-
servations, hence relying primarily on in-band spectral indexes
(Tab. A.2, see Sect. 4).
The spectral indexes between two frequencies were derived
modelling the spectrum as a power law following the usual defi-
nition:
α1,2=−
log10 S1
S2
log10 ν1
ν2(2)
For all of our sources we derived the in-band spectral index of
the peak flux αp, the in-band spectral index αin−band of the inte-
grated flux, and the spectral index α1.4−5between 1.4 and 5 GHz,
using the integrated flux we measured and the FIRST or NVSS
survey flux. The results are shown in Tab. A.2.
Using what we found, the three spectral classes we created
are the following.
– F sources: flat-spectrum radio-loud NLS1s (F-NLS1s) have
a flat or inverted radio spectrum around 5 GHz (α < 0.5).
Initially we examined the in-band spectral index of the to-
tal flux αin−band. When, including the error bars, the latter
satisfies the required criterion <0.5, we included the source
in this sample. When this was not the case, we compared
αin−band with the broad-band spectral index between 1.4 and
5 GHz, α1.4−5. We classified the source based on the mea-
surement with the lowest relative error. The total number of
objects in this sample is 28, including all but one of the γ-ray
emitters.
– S sources: S-NLS1s must have a steep radio spectrum (α >
0.5) in our measurements. To be included directly in this
sample, αin−band >0.5 within the error bars. Otherwise, in a
similar fashion to F objects, we compared it with α1.4−5and
chose according to the lowest relative error. With this selec-
tion, the number of S objects is 19, including the γ-ray source
J1102+2239 (Foschini et al. 2015). Both F-NLS1s and S-
NLS1s belong to the class of radio-loud NLS1s (RLNLS1s).
– Q sources: radio-quiet NLS1s (RQNLS1s) finally are radio-
quiet (R <10), but not radio-silent, that is they all have a
previous radio detection in FIRST or NVSS. This classifica-
tion did not change with respect to previous works published
in the literature (e.g. Berton et al. 2015). This subsample con-
tains 27 sources.
The redshift distributions of the four subsamples and the whole
sample are shown in Fig. 2. The median values are 0.437, 0.048,
and 0.225 for the F, Q, and S sample, respectively. For the whole
sample, the median redshift value is 0.160.
As a consistency check, we compared our in-band indexes,
calculated over the total flux, with the α1.4−5. The results of our
check are shown in Fig. 1. In the F sample the sources show
a widespread distribution of broad-band spectral indexes, while
the in-band index is instead often close to 0. However, as we al-
ready mentioned, the large variability observed in some of our
sources might affect this result, since beamed relativistic jet can
vary on very short time scales (Foschini et al. 2015; Kshama
et al. 2017). Our result seems to confirm this impression: the
Fig. 3. The redshift distribution of the three morphological sam-
ples. From top to bottom, C, I, and E sample.
broad-band index derived from non-simultaneous observations
is often unreliable, and very different from the (flat) in-band in-
dex, because of this issue.
Also radio-quiet NLS1s, at least in the optical, are known to
be variable (e.g. Shapovalova et al. 2012), but the effect should
be less extreme (Rakshit & Stalin 2017). Indeed, in the Q sam-
ple, the majority of our sources have in- and broad-band indexes
consistent with each other within the errors. It is worth noting
that error bars, especially those of αin−band, are very large. This
is due to the low luminosity of Q objects, which inevitably af-
fected our measurements. We also highlight that the majority of
Q objects lie below the 1:1 ratio. The broad-band index seems
then to be steeper with respect to the in-band one. Finally, the S
sample has also very large errors, but on average the two mea-
surements are consistent.
5. Physical properties
The results of our measurements are shown in Tab. A.3, and
Tab. A.4 .
5.1. Morphology
Another result that can be derived from maps is a morphological
classification of the sources. We divided them into three classes,
according to the ratio between the peak and the total flux density
of each source, R=Sp/Sint:
– Compact: labeled as C in the last column of Tab. 1, are those
sources with R ≥ 0.95;
– Intermediate: all sources with R<0.95 and R ≥ 0.75, they
are labeled as I in Tab. 1;
– Extended: all the remaining sources (R<0.75). They are
labeled as E in Tab. 1.
The thresholds were selected in such a way that the classifi-
cation reflects as much as possible the properties of the sources
as seen in the maps. The morphological distributions of the sam-
ples are shown in Tab. 2. The three morphological classes are
almost equally represented in the sample. The majority is made
of compact sources (36%), followed by a 35% of I sources, and
a 28% of extended sources. However, the single subsamples sig-
nificantly differ from each other. Among F sources, more than
5
M. Berton et al.: NLS1s with JVLA
Table 2. Morphological distribution of the sources.
Sample C I E
Total 27 (36%) 26 (35%) 21 (28%)
F 15 (54%) 10 (36%) 3 (11%)
Q 6 (22%) 9 (33%) 12 (44%)
S 6 (32%) 7 (37%) 6 (32%)
Notes. Columns: (1) sample; (2) compact sources; (3) intermediate
sources; (4) extended emission.
half are compact, while ∼1/3 have intermediate morphology and
only 11% has an extended emission. In the S sample, sources
are distributed almost uniformly among the three morphologies,
with a numerical predominance of intermediate morphologies.
Finally, radio-quiet objects exhibit an opposite behavior with re-
spect to F objects, often having a significant extended emission,
and less frequently compact (22%).
The morphological classification seems to have a depen-
dence on the redshift. This result is somewhat expected, since
distant sources are less likely to be resolved. As shown in Fig. 3,
sources with extended emission are typically concentrated at low
z, and the same is true for I sources, although their distribution
is slightly more uniform. The number of compact objects in-
stead increases almost linearly with z. However, there are objects
which show extended emission even at high z (e.g. the I source
J0814+5609, Fig. C.7, z =0.510), indicating a brightness of the
diffuse emission much larger than the average. Objects with such
large-scale emission would not be visible at smaller distances be-
cause of instrumental limitations. The JVLA A-configuration in
fact resolves-out all those structures with a size larger than ∼1800.
We cannot exclude then the presence of similar objects at low z.
In the following, along with the original classification used to
create the sample and based on the spectral indexes, the radio-
loudness, and the γ-ray detection, we will analyze the proper-
ties of the three morphological classes which, in principle, are
based on a less variable property of the sources. In particular,
the radio-loudness parameter is often considered to be somewhat
ambiguous (e.g. Ho & Peng 2001; Kharb et al. 2014; Foschini
2017; Padovani 2017). The spectral index measurements, partic-
ularly broad-band ones but also in-band, can be affected by the
strong variability of these sources, especially the beamed ones
(Foschini et al. 2015). Therefore, the spectral classification of
a source can change in time. For instance, the flat-spectrum γ-
ray emitter PKS 2004-447, was classified in the past as a com-
pact steep-spectrum source likely because of a different state of
activity (Oshlack et al. 2001; Gallo 2006). The morphological
classification hence is an helpful way around this variability is-
sue.
We determined the distribution of spectral indexes as a func-
tion of the morphological classification. The results are shown
in Fig. 4, and briefly summarized in Tab. 3. The data show that
the fraction of sources with a steep spectrum is higher in sources
with extended emission, while the compact one mainly show a
flat spectrum. Indeed, while compact sources have an average in-
band index of 0.36, both intermediate and extended sources are
on average above the αν=0.5 threshold. It is also worth men-
tioning that the interquartile range (IQR) of the three distribution
increases from C to E objects, with the largest spread found in
the E sample.
To statistically verify the differences between the samples,
we decided to use the Kolmogorov-Smirnov (K-S) test, that mea-
sures the distance between the cumulative distributions. The null
Fig. 4. Histogram of the in-band spectral index, calculated on
the integrated flux, in the three different morphological classes.
From top to bottom, C, I, and E. The vertical dashed line indi-
cates the position of the 0.5 value, which separates flat- from
steep-spectrum sources.
Fig. 5. The logarithm of integrated radio luminosity (5 GHz)
as a function of redshift. Colors and symbols are the same as
in Fig. 1. The dashed black line represents the JVLA detection
limit for our survey parameters (10 µJy, assuming αν=−1),
the dashed-dotted line represents the FIRST survey limit (1 mJy,
same spectral index as before).
hypothesis is that two brightness temperature distributions are
originated from the same population of sources. To reject the
null hypothesis, we require a confidence level of 5%, meaning
a p-value lower than 0.05. Indeed, the K-S test confirms this.
The only two samples for which it is possible to reject the null
hypothesis are the compact and extended sample (p-value 0.02).
This therefore indicates that the two distributions have not the
same origin, and that, not surprisingly, the extended sources have
intrinsically steeper spectra with respect to compact objects.
5.2. Luminosity
The integrated luminosity of our sources ranges between 1036
and 1044 erg s−1, increasing from radio-quiet to radio-loud ob-
6
M. Berton et al.: NLS1s with JVLA
Table 3. Statistics of the in-band spectral index for each mor-
phological class.
Sample Mean Median Std. dev. IQR N N (%)
C 0.36 0.12 0.67 0.58 8 29%
I 0.54 0.41 0.58 0.75 12 46%
E 0.71 0.77 0.75 0.99 13 65%
Notes. Columns: (1) sample; (2) mean in-band spectral index; (3) me-
dian spectral index; (4) standard deviation; (5) interquartile range; (6)
number of objects with αin−band >0.5; (7) percentage of steep-spectrum
sources.
Fig. 6. Logarithm of the diffuse luminosity as a function of the
logarithm of the total integrated luminosity. The black dashed
line is the 1:1 ratio, the black solid line is the linear best-fit of
the points. Colors and symbols as in Fig. 1.
jects as shown in Fig. 5. As expected, radio-quiet sources are
concentrated at low redshift and lower luminosities, while radio-
loud sources are predominant at larger distances. The logarithm
of the mean total luminosity for Q sources and the standard
deviation of the distribution are (38.67±0.77) erg s−1, while it
is (40.11±0.55) erg s−1and (41.57±1.15) erg s−1for S and F
sources, respectively.
In terms of peak luminosity, the results are very similar for
radio-loud sources, with mean values (41.52±1.16) erg s−1, and
(39.99±0.60) erg s−1for F and S samples. The largest difference
is observed in Q sources, in which the mean peak luminosity is
(38.53±0.87) erg s−1, which is ∼0.2 dex smaller than the inte-
grated luminosity. This is in agreement with the observed large
number of sources with extended emission in the Q sample.
If we limit our analysis only to the 6 γ-ray sources, the
luminosity appears to be the highest, with a mean value of
(42.39±1.00) erg s−1. Their peak luminosity, given their typi-
cally compact structure, is very similar, 42.34±0.99 erg s−1, and
is also the highest of the sample. It is worth noting that the four
out of the five most luminous sources in the samples are all γ-ray
emitters.
A relatively large fraction of F and S sources also shows
extended emission. The best-fit line shown in Fig. 6 has a
slope of 0.79±0.01, meaning that the diffuse luminosity, i.e.
the difference between integrated and peak luminosity, is larger
in brighter (radio-loud) sources than in fainter (radio-quiet)
sources. Q sources in fact lie close to the 1:1 ratio between total
and diffuse emission while, in our sample, the highest is the in-
Table 4. Properties of the optical spectra used to calculate the
new black hole masses.
Name Spectrum Date Exp. time (s) log M
J0347+0105 Asiago 2013-11-30 4800 7.33
J0629−0545 Asiago 2015-12-10 6000 7.80
J1114+3241 SDSS 2005-09-05 900 6.56
J1317+6010 SDSS 2002-05-16 900 6.59
J2242+2943 Asiago 2015-08-06 18000 6.51
Notes. Columns: (1) source name; (2) observatory; (3) observing date;
(4) exposure time (seconds); (5) logarithm of the black hole mass.
tegrated luminosity, the smallest becomes the contribution of the
extended emission with respect to the total luminosity.
5.3. Brightness temperature
The brightness temperature is usually calculated using very high
resolution observations. Therefore, our brightness temperature
measurements are all lower limits, because the sizes measured
from the deconvolution are only upper limits to the real size of
the core. However, our measurements are comparable with each
other, therefore this parameter can provide some useful insights
even in our case. We show the distribution of brightness temper-
atures as a function of the sample and the morphology in Fig. 7.
In those sources where the core size could not be determined, we
assumed a deconvolved size of the core equal to the average size
of each sample. The mean logarithmic value and standard devi-
ation for each one of our samples are 5.33±1.00, 3.15±0.98, and
3.51±0.98, for F, Q, and S samples, respectively. The value for
F sources is significantly different from those of the other two
samples. The different morphological groups instead have mean
values 4.78±1.49,3.96±1.01, and 3.21±1.10 for compact, inter-
mediate, and extended sources, respectively. The differences be-
tween these values seem to be less pronounced that those found
using the spectral classification.
We tested the possibility that the difference in brightness
temperature is connected with redshift. The Spearman rank cor-
relation coefficient between these two quantities is 0.52, with a
p-value of 2.0×10−6. This indicates only a trend between these
two quantities, and suggests that even if the redshift has some
impact on the brightness temperature, it is not its main driver.
In analogy with spectral indexes, we used again the K-S test
to verify whether the samples are actually different. The null hy-
pothesis, as before, is that the two samples are originated from
the same population of sources, and the p-value threshold is still
0.05. The K-S test indicates that F-NLS1s are well distinct in
terms of brightness temperature from both S-NLS1s and radio-
quiet objects. The p-values are indeed 2.7×10−5and 3.5×10−8,
respectively. Interestingly, the brightness temperature distribu-
tions of S and Q objects might instead be originated from the
same population of sources (p-value =0.46).
In terms of morphology, the results are similar, with the K-S
test convincingly distinguishing between compact and extended
sources (p-value 1×10−4). Also extended and intermediate ob-
jects seem to be different (p-value 0.02), and the same is true for
compact and intermediate objects (p-value =0.04).
Finally, it is worth mentioning that the six γ-ray sources in-
cluded in the sample have a median brightness temperature of
5.67±1.52, which is higher than the other samples. In particular,
J0849+5108 and J1505+0326 are the only two sources with a
brightness temperature above 107K.
7
M. Berton et al.: NLS1s with JVLA
Fig. 7. Brightness temperature distributions in the different sam-
ples. Left column, from top to bottom, F, Q, and S samples. Right
column, from top to bottom, C, I, and E morphology.
5.4. Black hole mass
Another fundamental property characterizing NLS1s is their
black hole mass. Almost all the values we used in this analy-
sis are those obtained in the papers by Foschini et al. (2015),
Berton et al. (2015), and Berton et al. (2016b). For J0006+2012
we used the value derived from reverberation mapping calcu-
lated by Grier et al. (2012). In five more cases, J0347+0105,
J0629−0545, J1114+3241, J1317+6010, and J2242+2943, we
calculated the black hole mass using either SDSS or new spec-
tra obtained with the Asiago 1.22m telescope (grism 300 mm−1,
R∼700, summary in Tab. 4), and following the same procedure
already described in detail by Foschini et al. (2015). We briefly
summarize it here. We corrected the spectra for redshift and
Galactic absorption (NHvalues from Kalberla et al. 2005), and
we subtracted the continuum and the Fe II multiplets (Kovaˇ
cevi´
c
et al. 2010; Shapovalova et al. 2012). We reproduced the Hβpro-
file using three Gaussians, two to represent the broad component
and one to represent the narrow. We estimated then the second-
order moment of broad Hβas a proxy for gas velocity. The BLR
radius was calculated from the Hβflux following Greene et al.
(2010). Assuming that the gas is virialized and that the scaling
factor is equal to 3.85 (Peterson et al. 2004; Collin et al. 2006),
we derived the black hole mass.
The resulting distribution is showed in Fig. 8. In terms of
spectral classification, the mean logarithmic black hole mass val-
ues (in Munits) and the standard deviation in each sample are
7.46±0.61, 7.13±0.46, and 7.76±0.41 for F, Q, and S sample, re-
spectively. As done before, we tested the different distributions
by means of the K-S test. The null hypothesis in this case can be
rejected when the Q sample is compared with both the F (p-value
=0.02) and the S sample (p-value =9×10−5). Conversely, it can-
not be rejected when F and S samples are compared (p-value =
0.25). This therefore suggests that, while F and S mass distribu-
tions might be drawn from the same population, Q sources could
be different in terms of black hole mass.
From a morphological point of view, we did not find any
significant difference between the samples. The mean logarith-
mic values of the black hole masses in this case are 7.55±0.45,
7.38±0.53, and 7.28±0.70 for C, I, and E sources, respectively.
Unlike before, these values are very close to each other. The K-S
Fig. 8. Black hole mass distributions in the different samples.
Left column, from top to bottom, F, Q, and S sample. Right col-
umn, from top to bottom, C, I, and E morphology.
test indeed does not allows us to reject the null hypothesis (p-
values 0.19 C-I, 0.16 C-E, 0.50 E-I), suggesting that the black
hole mass does not have a strong impact on the source morphol-
ogy.
Lastly, the six γ-ray sources have a median logarithmic mass
of 7.72, with a standard deviation of 0.40 inside the sample. This
value is not significantly different neither from that of F sources,
nor from that of S sources, as confirmed by the K-S test (p-values
0.46 and 0.76, respectively).
6. Discussion
6.1. Origin of the radio emission
The first aspect that we highlight is that each one of the three
spectral classes seem to have their own, particular, physical
properties. F-NLS1s are typically compact, very bright in the
radio and, as a consequence, they typically have a fairly high
brightness temperature. In particular, the γ-ray sources, which
are almost all concentrated in this class, are the most extreme
objects in terms of the brightness temperatures. S-NLS1s are
instead somewhat intermediate sources, which typically neither
are compact nor show an extended emission. Their luminosity
is on average lower than that of F-NLS1s, and the same is true
for their brightness temperatures. Both radio-loud classes can
be found up to high z. Obviously, given their higher luminos-
ity, F sources are most common at larger distances, but the far-
thest source, J1348+2622 (z =0.966), belongs to the S class.
RQNLS1s instead seem to be rather different from both the other
classes. Firstly, they are located at lower z, but this is very likely
a selection effect. Faint NLS1s were not included in the FIRST
because of their weak emission below the detection limit of the
survey, and consequently they were excluded from our survey.
Furthermore, radio-quiet NLS1s often exhibit large scale struc-
tures and they have a relatively low brightness temperature.
This rather clear separation between the samples might be
interpreted in terms of different origin of the radio emission and
incidence of relativistic beaming. F-NLS1s, in analogy with the
other classes of blazars, are observed inside their relativistic jet,
and their radio emission is due to optically thick synchrotron
radiation. The relativistic beaming enhances greatly both their
8
M. Berton et al.: NLS1s with JVLA
brightness temperature and their luminosity, making them visi-
ble at large distances. S-NLS1s are instead observed at larger an-
gles, therefore the effect of beaming is less evident, and the radio
spectrum becomes dominated by the optically thin sinchrotron
radiation of the jet. This scenario is nothing new, but it confirms
what we already knew of these objects.
In radio-quiet objects the situation is instead less clear. Their
brightness temperature distribution and their spectral indexes are
similar to those of S-NLS1s, thus suggesting that the presence
of a misaligned relativistic jet cannot be ruled out. Some ex-
amples are already known. J0952-0136 harbors a pc-scale rela-
tivistic jets observed with VLBA (Doi et al. 2015), and our map
reveals indeed a faint diffuse emission around its core. Its bright-
ness temperature is the highest in the Q sample (∼8.3×104K), a
value which is also above the median of the S sample. There
is at least another source with similar brightness temperature
and morphology, J1337+2423, which in our map (see Fig. C.26)
shows a marginally resolved structure extended for ∼7 kpc. No
high-resolution images are available for this source, but it could
represent another example of a jetted RQNLS1.
In several cases instead the low radio luminosity of
RQNLS1s is associated with a very low brightness temperature.
This might indicate that in such sources the origin of the radio
emission is not a misaligned relativistic jet, but instead star for-
mation. NLS1s are well-known to be objects with a very high
circumnuclear star formation rate (Sani et al. 2010), possibly
due to the fact that these sources are young or rejuvenated by
galaxy mergers (Mathur 2000; Mathur et al. 2012; Le´
on Tavares
et al. 2014). The same appears to be true in many RLNLS1s:
Caccianiga et al. (2015) estimated the q22 parameter, defined as
q22 =log S22 µm
S1.4GHz
(3)
where S22µmis the flux density at 22µm derived from the
WISE colors, and S1.4GHz is the flux density at 1.4 GHz. A high
q22 (e.g. ∼1), when associated with a high level of star formation
rate, might suggest that a large fraction of the radio emission
could be attributed to the ongoing star formation. Many of the
radio-loud sources common to their and our sample that have
a high q22, also have a low brightness temperature, seemingly
confirming this hypothesis.
6.2. Comparison to other surveys
Our survey is the largest survey aimed at imaging the radio
continuum emission in NLS1 carried out at this frequency so
far. Richards & Lister (2015) performed a similar study at 7.6
GHz on three objects. They randomly selected three sources,
and found kpc-scale emission in all of them. In our study we
found several sources showing extended emission, and indeed
their number is fairly high. As discussed in Sect. 5.1, among
our 47 RLNLS1s 26 show an intermediate or extended mor-
phology (∼55% of the total). Unlike them, though, we do not
find many objects clearly showing a fully developed, large scale
one-sided relativistic jet. Only a few objects, like J0814+5609
or J1110+3653 have similar morphology and projected size to
those sources. Both of them anyway show a flat radio spectrum,
likely because of the overwhelming core contribution. Many of
the other objects instead have smaller projected sizes, possi-
bly suggesting a low inclination, as expected from type 1 (and
beamed) AGN.
At 5 GHz Gu et al. (2015) investigated a small sample of
14 RLNLS1 with VLBA. With the only exception of SDSS
J095317.09+283601.5, their sample is completely included in
ours. In general, it appears that those sources resolved on VLBA
scales show a similar structure on the larger VLA scales. Only
one exception can be found, that is J1548+3511. As seen in
Fig. C.32, on the VLA scales it is compact, while its VLBA im-
age reveals a well resolved core-jet structure which, given its size
(∼350 pc), is entirely inside our unresolved core (∼700×300pc).
In other cases, the extended emission they detect is clearly seen
also in sources which are strongly compact. An interesting dif-
ference is found in J0902+0443, which in their study shows a
jet pointing toward North-East, while in our case we found signs
of diffuse emission toward South-East (see Sect. B.17), possibly
suggesting a change in jet direction.
Another small NLS1 survey at 5 GHz was performed by
Ulvestad et al. (1995) to complete the radio characterization of
the sample objects with spectropolarimetric observations from
Goodrich (1989). Only two of the 7 NLS1s observed in this pa-
per are included in our sample: Mrk 766 and Mrk 1239. The
objects were observed with the same VLA configuration we are
using but only Mrk 766 was “partially” resolved. We observe a
similar morphology in Mrk 766 (Fig. C.21), with more diffuse
emission, and a well defined extended structure on both sides of
the nucleus of Mrk 1239 (Fig C.12), at the same position angle
of the emission detected by Doi et al. (2013) at 1.7 GHz with the
VLBA.
Our radio-quiet objects often show significant faint extended
emission, located around an unresolved core. Doi et al. (2013)
investigated seven of these sources, all included in our sample,
at 1.7 GHz using VLBA. All of those sources revealed a high
brightness temperature, suggesting a non-thermal origin of the
radio emission. In our sample, all these sources belong to the
I or E class, showing a significant extended emission on kpc
scale. On VLBA scale, instead, only three of them show signs
of extended emission on 10-pc scale, while the others are com-
pact or not-detected. This indicates that the extended emission is
resolved-out by VLBI observations.
6.3. F-NLS1s and other blazars
One of the first observations of blazars with the VLA in A-
configuration were carried out at 1.4 GHz by Antonucci &
Ulvestad (1985). Despite the much lower sensitivity with respect
to that of present-day JVLA, they found that those sources had
a powerful kpc-scale extended emission in some cases compara-
ble to that of FR II doubles, thus confirming the unification be-
tween blazars and radio galaxies. Subsequent observations with
the VLA confirmed this result, suggesting that both BL Lacs and
FSRQs can be associated with an FR II-like extended emission
(Murphy et al. 1993; Cooper et al. 2007; Kharb et al. 2010),
even though different associations between these classes of ob-
jects can be found in the literature (Urry & Padovani 1995). Our
maps of F-NLS1s do not show anything comparable. Although
some extended emission in some cases is present, only 3 out
of 28 F sources clearly show diffuse emission with a luminos-
ity comparable to that of the core, and two of them are in the
top-5 of our most luminous sources. Ten of them instead show
some diffuse emission, which is however not comparable to that
observed in blazars. Similar results, although at different scales,
were already found in previous studies (Doi et al. 2006; Yuan
et al. 2008; Foschini et al. 2011; Giroletti et al. 2011).
This difference in terms of extended emission suggests that
F-NLS1s and FSRQs have different physical properties. As al-
ready mentioned, one of the possible interpretations regarding
the nature of NLS1s is that they are a projection effect due to the
9
M. Berton et al.: NLS1s with JVLA
lack of Doppler broadening in a disk-like BLR viewed pole-on
(Decarli et al. 2008). Several authors suggested that this is true
for F-NLS1s as well, which would have a black hole mass com-
parable to that of typical FSRQs (Calderone et al. 2013). If this
were true, F-NLS1s should show powerful extended emission,
just like other FSRQs. Since they do not, we conclude that they
are not the same class of sources.
Given that the typical luminosity of F-NLS1s is lower than
that of FSRQs, it is possible that the former are the low-
luminosity version of the latter (Foschini et al. 2015; Berton
et al. 2016a). Additionally, since the jet power scales with the
black hole mass (Heinz & Sunyaev 2003; Foschini 2014) F-
NLS1s might also be low-mass, possibly young, FSRQs that, un-
like the latter, are not usually capable of producing radio lobes.
In fact, if NLS1s are young objects, their relativistic jets might
not have had enough time to develop the extended emission yet
(Berton et al. 2015). Conversely, sources such as J0814+5609,
J1110+3653, or J1633+4718, might be instead slightly older ob-
jects which already managed to form the radio lobes. This young
age hypothesis could account for the relative rarity of radio lobes
among RLNLS1s, and give RQNLS1s a role to play in the parent
population problem (see Sect. 6.4).
6.4. Parent population
Several authors have already suggested a possible link between
CSS sources and RLNLS1s (Oshlack et al. 2001; Gallo 2006;
Komossa et al. 2006; Gu et al. 2015; Caccianiga et al. 2014,
2017; Berton et al. 2016a). A possibility is that CSS are the mis-
aligned counterpart of F-NLS1s (their parent population), with
S-NLS1s, in particular those with high luminosity, being a pop-
ulation of type 1 CSS sources (Berton et al. 2017). Typical CSS
sources indeed have a double-sided morphology (e.g. Saikia
et al. 2003; Dallacasa et al. 2013; Orienti 2016), an indication
that their inclination is large like in type 2 AGN. CSS sources by
definition have powerful extended emission, with log P1.4≥25
W Hz−1. This value corresponds at 1.4 GHz to log (νFν)≥41.15
erg s−1, and using αν=1, at 5 GHz it is log (νFν)≥40.60 erg
s−1. Furthermore, CSS have a small size (between 1 and 20 kpc)
and a convex radio spectrum that peaks in the MHz range and
steepens toward higher frequencies (O’Dea 1998).
Whilst the small size and convex spectrum at radio wave-
lengths can be true for NLS1s as well (Caccianiga et al. 2017),
the condition on luminosity is not always respected. Several
RLNLS1s are indeed below that threshold (see Fig. 5), espe-
cially because, unlike CSS, they often do not have powerful ex-
tended emission. CSS sources indeed on VLBI scales very of-
ten exhibit a complex morphology (Dallacasa et al. 2013), while
RLNLS1s have a simpler core-jet or compact structure (Gu &
Chen 2010). On VLA scale the situation is not different. Around
∼33% of CSS sources are compact, while the others show dou-
ble or triple morphology, or a core-jet structure (Fanti et al.
2001). Among our RLNLS1s the percentage of compact sources
is slightly higher (∼44%), while only a few doubles and core-jet
structures are present.
RLNLS1s seem also to share several aspects with the
low-power CSS studied by Kunert-Bajraszewska et al. (2010),
particularly those classified as high-excitation radio galaxies
(HERGs), which typically show less disturbed morphology with
respect to higher-luminosity CSS (Kunert-Bajraszewska et al.
2006). These objects might be short-lived sources, whose ac-
tivity is switched on and offby disk instabilities (Czerny et al.
2009). RLNLS1s might also show intermittent activity due to
the same physical mechanism. An aborted jet has often been in-
voked to explain their radio emission (Ghisellini et al. 2004),
and the occurrence of this phenomenon was maybe observed in
X-rays (Wilkins et al. 2015). One of our sources, J1302+1624,
is also a possible example of intermittent activity, since its ex-
tended emission might be associated with a relic (Congiu et al.
2017a).
A more proper unification might then be sought between
these low-luminosity CSS and RLNLS1s. However, another op-
tion exists. The flux density of beamed objects is Sbeam =δ3−αν
Sunb, where Sbeam is the observed beamed flux density, Sunb is
the unbeamed flux density, δis the kinematic Doppler factor of
the jet, and ανis the intrinsic slope of the jet power-law (that
we assume to be αν=1). Knowing that δ=[Γ(1 −βcos θ)]−1,
where θis the observing angle (∼0◦for a blazar), β=v/c, and
Γis the bulk Lorentz factor of the jet. A flux density of ∼50
mJy, similar to that of the γ-ray source J1305+5116, if Γ∼10
(Abdo et al. 2009b) and β=0.99, corresponds to an unbeamed
flux of 0.5 mJy, which is below the detection limit of FIRST. If
observed at large angles then a bright source like J1305+5116
would appear as radio-silent, hence it could not be included in
our sample. Radio-silent objects might therefore harbor hidden
relativistic jets, and be part of the parent population. This aspect
was already investigated in Berton et al. (2016b) by means of
the [O III] lines. They found that the number of blue outliers,
that is sources with [O III] blue-shifted with respect to their rest-
frame position, is much larger in RLNLS1s than in radio-quiet
and radio-silent objects. This suggests interaction between the
relativistic jet and the narrow-line region occurring in radio-loud
objects, and the lack of it in radio-quiet/silent sources. However,
another interpretation could account for this phenomenon. Some
authors (e.g. Boroson 2011; Risaliti et al. 2011; Bisogni et al.
2017) affirm that the [O III] emission line can be used as an in-
clination indicator. In particular Boroson (2011) focused on the
blueshifted component. If sources with a large blueshift are those
observed pole-on, this could mean that the lack of blue outliers
among radio-quiet NLS1s could be due to their large viewing
angle, instead of the lack of a relativistic jet interacting with the
interstellar medium.
In this scenario, radio-quiet NLS1s are part of the parent
population of F-NLS1s. However, an important property seems
to indicate that RQNLS1s and S-NLS1s are very different ob-
jects. Their black hole mass distributions, indeed, are signifi-
cantly different, as confirmed by the K-S test. The possible im-
pact of redshift on this difference is not clear. Low redshift might
in fact enable us to see faint sources that, because of the mass
scaling, harbor low-mass black holes. However, it is also worth
noting that all S sources of our samples have a black hole mass
larger than 107Mregardless of z, while a significant fraction of
Q objects lie below this value. To test this difference, we carried
out the K-S test limiting the two samples (Q and S) at z <0.3,
and the result does not change: the null hypothesis is rejected
again (p-value =8×10−3).
Curiously, several F sources also fall below the 107M
threshold. A possible interpretation for this might be the pres-
ence of a flattened BLR in some objects, that leads to an underes-
timate of the black hole mass even when using the second-order
moment of the permitted line, as it was done in our case. The
”real” masses would then be closer to those found for S sources,
which on average are 7×107M, in the high-mass tail of the
NLS1s distribution (but below the typical mass of FSRQs).
Finally, the morphology of Q objects appears to be different
with respect to radio-loud NLS1s. In Q sources a faint, diffuse
emission is present in many cases, their unresolved cores are
much fainter, and a larger contribution of star formation to the to-
10
M. Berton et al.: NLS1s with JVLA
tal emission appears plausible. We cannot exclude, though, that
our objects are different only because of a selection effect due
to their low redshift. In order to obtain an unbiased comparison,
one should study radio-quiet/silent objects at higher redshift, to
test whether faint relativistic jets are present and they belong to
the parent population of F-NLS1s.
7. Summary
We have presented the first results of a survey on 74 NLS1s
carried out with the JVLA. The sources were divided accord-
ing to their radio properties into radio-quiet (Q), flat-spectrum
radio-loud (F), and steep-spectrum radio-loud (S). Additionally,
we classified the sources based on their morphology into com-
pact (C), intermediate (I), and extended (E). We found that the
majority of F sources has a compact morphology, a high lumi-
nosity, high redshift, and high brightness temperature, signs that
these objects are basically low-luminosity blazars, that is objects
observed inside their relativistic jet. S objects instead show of-
ten intermediate or extended morphology, and lower luminosity
and brightness temperature with respect to F objects, although
they remain brighter than Q sources. The latter instead often
show a faint diffuse emission on kpc scale which surrounds the
unresolved core. Their brightness temperature is comparable to
that of S sources, but given their different morphology its ori-
gin might be found in star formation instead of jet activity. The
black hole mass distributions confirms that S sources are part
of the F parent population, while the connection between F and
Q objects is unclear. We also notice how several shared charac-
teristics seem to indicate that low-luminosity CSS sources, and
some classical CSS as well, might also be part of F-NLS1s par-
ent population. To understand the role of Q sources, a dedicated
survey at higher redshift is needed, in order to find out whether
faint misaligned relativistic jets are present also in this class of
objects. An upcoming paper with analyze in detail the morphol-
ogy and the properties of extended sources, both radio-quiet and
radio-loud, in order to compare them with CSS and other AGN
classes.
Acknowledgements. The authors are deeply grateful to Dr. M. Giroletti for
the helpful discussion about the JVLA data reduction. The National Radio
Astronomy Observatory is a facility of the National Science Foundation op-
erated under cooperative agreement by Associated Universities, Inc. This pa-
per is based on observations collected with the 1.22m Galileo telescope of
the Asiago Astrophysical Observatory, operated by the Department of Physics
and Astronomy ”G. Galilei” of the University of Padova. This work has
been partially supported by PRIN INAF 2014 “Jet and astro-particle physics
of gamma-ray blazars” (P.I. F. Tavecchio). This research has made use of
the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet
Propulsion Laboratory, California Institute of Technology, under contract with
the National Aeronautics and Space Admistration.
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12
M. Berton et al.: NLS1s with JVLA
Appendix A: Tables
Table A.1. Observational details.
Short name Date Exposure Short name Date Exposure
J0006+2012 2015-07-05 538 J1159+2838 2015-08-14 506
J0100-0200 2015-07-05 538 J1203+4431 2015-09-05 566
J0146-0040 2015-07-05 538 J1209+3217 2015-09-05 568
J0347+0150 2015-07-05 538 J1215+5442 2015-09-05 568
J0629-0545 2015-07-10 506 J1218+2948 2015-08-14 506
J0632+6340 2015-07-10 536 J1227+3214 2015-08-14 506
J0706+3901 2015-07-10 536 J1238+3942 2015-09-05 568
J0713+3820 2015-07-10 536 J1242+3317 2015-09-06 552
J0744+5149 2015-07-14 536 J1246+0222 2015-09-06 552
J0752+2617 2015-08-14 506 J1246+0238 2015-09-06 552
J0754+3920 2015-07-10 506 J1302+1624 2015-09-06 552
J0804+3853 2015-07-10 508 J1305+5116 2015-08-30 566
J0806+7248 2015-07-14 536 J1317+6010 2015-08-30 552
J0814+5609 2015-07-14 536 J1333+4141 2015-08-30 566
J0849+5108 2015-07-10 506 J1337+2423 2015-09-04 536
J0850+4626 2015-08-01 508 J1346+3121 2015-09-04 538
J0902+0443 2015-07-28 492 J1348+2622 2015-09-04 538
J0913+3658 2015-08-15 716 J1355+5612 2015-08-30 550
J0925+5217 2015-08-01 506 J1358+2658 2015-09-03 596
J0926+1244 2015-07-28 492 J1402+2159 2015-09-03 596
J0937+3615 2015-08-15 714 J1421+2824 2015-09-03 596
J0945+1915 2015-08-14 506 J1443+4725 2015-08-29 652
J0948+5029 2015-08-01 506 J1505+0326 2015-09-01 654
J0952-0136 2015-07-28 492 J1536+5433 2015-08-29 656
J0957+2444 2015-08-14 506 J1537+4942 2015-08-29 654
J1031+4234 2015-08-29 594 J1548+3511 2015-07-23 522
J1034+3938 2015-08-29 594 J1555+1911 2015-09-01 654
J1037+0036 2015-07-28 492 J1559+3501 2015-07-23 522
J1038+4227 2015-08-29 594 J1612+4219 2015-07-23 522
J1047+4725 2015-08-29 594 J1629+4007 2015-07-23 522
J1048+2222 2015-08-29 596 J1633+4718 2015-07-22 536
J1102+2239 2015-08-29 596 J1634+4809 2015-07-22 536
J1110+3653 2015-08-14 598 J1703+4540 2015-07-22 538
J1114+3241 2015-08-15 596 J1709+2348 2015-09-01 638
J1121+5351 2015-08-29 596 J1713+3523 2015-09-01 640
J1138+3653 2015-08-15 598 J2242+2943 2015-07-02 596
J1146+3236 2015-08-15 596 J2314+2243 2015-07-02 596
Notes. Columns: (1) short name; (2) observation date; (3) exposure time
(s); (4) short name; (5) observation date; (6) exposure time (s).
Appendix B: Notes on single objects
In the following, unless otherwise specified, when they are
present the reference for 22 GHz VLBI measurement is Doi et al.
(2016), that for 37 GHz with the Mets¨
ahovi 14m radio telescope
is L¨
ahteenm¨
aki et al. (2017), and that for the q22 parameter and
star formation rate is Caccianiga et al. (2015).
B.1. J0006+2012
Mrk 335, a well-known radio-quiet NLS1, was already ob-
served at 5 GHz by Edelson (1987) with the Owen Valley Radio
Telescope (OVRO), finding a flux of 3.30±0.18, which is es-
sentially identical to our result. Another observation was car-
ried out more recently with the VLA in A configuration (Leipski
et al. 2006), finding a point source and a total flux of 3.58±0.05
mJy, slightly larger than our measurement. Our map, shown in
Fig. C.1 shows an unresolved core, with a source size decon-
volved from beam of 50×28 pc.
B.2. J0100−0200
FBQS J0100-0200 was one of the sources included bona-fide
(i.e. without a measured spectral index) in the F sample by
Foschini et al. (2015). While the broad-band index is consis-
Table A.2. Spectral indexes of the sources. The 1.4 GHz data are
derived from FIRST or NVSS.
Short name αpαin−band α1.4−5
J0006+2012 0.77 ±0.06 0.78 ±0.20 0.18 ±0.18
J0100−0200 0.77 ±0.07 0.83 ±0.23 0.34 ±0.08
J0146−0040 -3.31 ±1.36 0.06 ±4.05 3.65 ±0.32
J0347+0105 0.34 ±0.07 -0.03 ±0.09 0.71 ±0.03
J0629−0545 0.14 ±0.01 -0.03 ±0.05 0.61 ±0.03
J0632+6340 0.83 ±0.09 0.71 ±0.10 1.12 ±0.06
J0706+3901 0.84 ±0.11 0.75 ±0.43 0.57 ±0.10
J0713+3820 0.89 ±0.11 1.04 ±0.23 0.96 ±0.05
J0744+5149 1.25 ±0.05 1.29 ±0.23 1.14 ±0.05
J0752+2617 3.23 ±1.11 1.68 ±3.66 1.38 ±0.22
J0758+3920 0.65 ±0.20 0.73 ±0.38 0.75 ±0.10
J0804+3853 1.79 ±0.46 1.47 ±0.88 0.92 ±0.09
J0806+7248 0.06 ±0.01 0.03 ±0.06 1.10 ±0.03
J0814+5609 0.02 ±0.01 0.08 ±0.03 0.55 ±0.03
J0849+5108 0.02 ±0.01 0.01 ±0.01 0.14 ±0.02
J0850+4626 0.20 ±0.02 0.18 ±0.06 0.34 ±0.04
J0902+0443 0.01 ±0.01 0.01 ±0.01 0.33 ±0.02
J0913+3658 1.40 ±2.02 1.36 ±2.52 0.95 ±0.18
J0925+5217 0.25 ±0.16 0.77 ±0.46 0.81 ±0.07
J0926+1244 0.74 ±0.06 0.46 ±0.19 1.83 ±0.04
J0937+3615 1.39 ±0.19 0.91 ±0.47 0.89 ±0.07
J0945+1915 0.92 ±0.05 0.92 ±0.12 0.80 ±0.04
J0948+5029 0.71 ±0.10 0.29 ±0.32 0.89 ±0.08
J0952-0136 0.08 ±0.03 0.04 ±0.05 0.77 ±0.03
J0957+2433 0.49 ±0.46 2.68 ±2.19 2.52 ±0.14
J1031+4234 0.59 ±0.02 0.56 ±0.10 0.97 ±0.03
J1034+3928 0.06 ±0.02 0.11 ±0.21 0.80 ±0.05
J1037+0036 0.01 ±0.01 0.01 ±0.03 0.24 ±0.03
J1038+4227 0.56 ±0.10 0.77 ±1.31 0.07 ±0.18
J1047+4725 0.47 ±0.16 0.07 ±0.01 0.57 ±0.02
J1048+2222 0.34 ±0.45 1.62 ±1.55 1.04 ±0.14
J1102+2239 1.23 ±0.26 1.46 ±1.61 0.97 ±0.21
J1110+3653 0.01 ±0.04 0.08 ±0.10 0.54 ±0.05
J1114+3241 0.03 ±0.01 0.01 ±0.03 -0.46 ±0.07
J1121+5351 0.91 ±0.23 0.70 ±0.43 0.56 ±0.17
J1138+3653 0.06 ±0.03 -0.03 ±0.12 0.72 ±0.04
J1146+3236 0.02 ±0.01 -0.01 ±0.03 -0.20 ±0.04
J1159+2838 1.22 ±0.18 0.79 ±0.54 0.71 ±0.10
J1203+4431 0.71 ±0.08 1.47 ±0.39 2.08 ±0.05
J1209+3217 0.93 ±0.33 0.54 ±0.73 0.63 ±0.08
J1215+5442 1.08 ±0.25 1.12 ±0.51 1.00 ±0.06
J1218+2948 0.24 ±0.09 0.06 ±0.06 0.75 ±0.03
J1227+3214 0.66 ±0.13 0.65 ±0.23 0.49 ±0.05
J1238+3942 -0.30 ±0.02 -0.32 ±0.04 -0.38 ±0.04
J1242+3317 1.29 ±0.12 0.77 ±0.27 0.71 ±0.08
J1246+0222 0.38 ±0.34 -0.37 ±0.56 0.87 ±0.07
J1246+0238 0.29 ±0.01 0.25 ±0.02 0.44 ±0.03
J1302+1624 0.70 ±0.15 2.71 ±0.25 0.65 ±0.04
J1305+5116 -0.12 ±0.01 0.06 ±0.02 0.37 ±0.02
J1317+6010 0.05 ±0.29 0.47 ±0.69 0.53 ±0.07
J1333+4141 0.67 ±0.32 0.67 ±1.81 0.76 ±0.07
J1337+2423 0.02 ±0.02 -0.05 ±0.05 0.47 ±0.03
J1346+3121 -0.79 ±0.03 -0.89 ±0.07 -1.00 ±0.07
J1348+2622 1.48 ±0.45 2.07 ±0.91 0.99 ±0.09
J1355+5612 0.02 ±0.11 0.01 ±0.45 0.83 ±0.08
J1358+2658 0.72 ±0.30 0.21 ±0.64 1.17 ±0.17
J1402+2159 1.02 ±0.40 0.77 ±0.97 2.16 ±0.09
J1421+2824 0.03 ±0.01 0.03 ±0.03 0.45 ±0.04
J1443+4725 0.04 ±0.01 0.02 ±0.01 0.53 ±0.02
J1505+0326 0.01 ±0.01 -0.01 ±0.01 -0.01 ±0.02
J1536+5433 0.65 ±0.34 0.35 ±0.96 0.67 ±0.11
J1537+4942 0.41 ±0.19 0.29 ±0.52 0.39 ±0.08
J1548+3511 0.02 ±0.01 0.01 ±0.02 0.60 ±0.02
J1555+1911 2.29 ±1.06 1.11 ±1.04 0.96 ±0.09
J1559+3501 1.26 ±0.52 1.46 ±0.27 1.11 ±0.08
J1612+4219 -0.24 ±1.36 -0.81 ±0.58 1.12 ±0.21
J1629+4007 0.01 ±0.01 0.01 ±0.02 -0.96 ±0.04
J1633+4718 0.03 ±0.01 0.02 ±0.03 0.75 ±0.02
J1634+4809 0.52 ±0.04 0.50 ±0.10 0.25 ±0.02
J1703+4540 0.13 ±0.02 0.04 ±0.02 0.95 ±0.02
J1709+2348 1.51 ±0.43 0.18 ±0.85 1.16 ±0.10
J1713+3523 1.03 ±0.04 0.94 ±0.11 0.85 ±0.04
J2242+2943 1.37 ±0.04 0.86 ±0.09 0.78 ±0.03
J2314+2243 0.03 ±0.03 -0.01 ±0.11 0.71 ±0.05
Notes. Columns: (1) short name; (2) in-band spectral index of the peak
flux; (3) in-band spectral index of the integral flux; (4) spectral index
between 1.4 and 5 GHz.
13
M. Berton et al.: NLS1s with JVLA
Table A.3. Geometrical properties of the sources. Missing values indicate an unresolved core.
Short name Beam maj Beam min Beam P.A. Core maj Core min Core P.A.
J0006+2012 0.46 0.43 +38.40 0.095 ±0.016 0.054 ±0.041 14 ±21
J0100−0200 0.55 0.40 +17.93 0.084 ±0.020 0.065 ±0.022 19 ±65
J0146−0040 0.54 0.38 −174.08 <0.39 <0.18
J0347+0105 0.52 0.38 −9.64 0.330 ±0.011 0.185 ±6.900 169 ±2
J0629−0545 1.49 0.44 −54.31 0.297 ±0.014 0.183 ±0.004 111 ±3
J0632+6340 0.80 0.40 −84.06 0.251 ±0.065 0.219 ±0.068 83 ±89
J0706+3901 1.09 0.58 −57.69 0.508 ±0.033 0.257 ±0.039 154 ±6
J0713+3820 1.09 0.51 −59.99 0.526 ±0.029 0.266 ±0.060 169 ±6
J0744+5149 0.82 0.38 −73.18 0.122 ±0.027 0.058 ±0.029 64 ±22
J0752+2617 1.17 0.39 +61.90
J0758+3920 1.15 0.53 −54.23 1.218 ±0.053 0.416 ±0.025 143 ±2
J0804+3853 0.45 0.41 +51.27 0.590 ±0.061 0.363 ±0.057 128 ±10
J0806+7248 0.73 0.40 −85.95 0.141 ±0.007 0.117 ±0.002 89 ±7
J0814+5609 0.82 0.37 −72.62 0.075 ±0.007 0.031 ±0.004 122 ±5
J0849+5108 0.43 0.41 +14.12 0.048 ±0.001 0.038 ±0.002 28 ±7
J0850+4626 0.48 0.42 −53.08 0.060 ±0.007 0.056 ±0.010 31 ±75
J0902+0443 1.35 0.41 +55.57 0.058 ±0.017 0.036 ±0.013 81 ±42
J0913+3658 1.18 0.41 −62.63 0.346 ±0.192 0.178 ±0.030 113 ±7
J0925+5217 0.54 0.46 −88.78 0.283 ±0.021 0.186 ±0.022 101 ±11
J0926+1244 0.94 0.41 +58.26 0.166 ±0.056 0.103 ±0.026 90 ±24
J0937+3615 1.29 0.41 −61.46 0.463 ±0.095 0.314 ±0.015 122 ±19
J0945+1915 0.72 0.42 +66.87 0.114 ±0.013 0.077 ±0.034 165 ±70
J0948+5029 0.52 0.45 −83.83 0.145 ±0.018 0.044 ±0.026 97 ±12
J0952−0136 0.94 0.45 +45.40 0.207 ±0.018 0.082 ±0.005 46 ±2
J0957+2433 0.69 0.41 +69.47
J1031+4234 0.50 0.43 +81.12 <0.11 <0.02
J1034+3938 0.56 0.45 +52.83 0.118 ±0.008 0.080 ±0.010 84 ±9
J1037+0036 0.65 0.41 +42.82 0.056 ±0.006 0.014 ±0.012 49 ±6
J1038+4227 0.54 0.45 +56.01 0.129 ±0.037 0.116 ±0.062 98 ±77
J1047+4725 0.40 0.31 −74.46 0.474 ±0.016 0.165 ±0.013 127 ±2
J1048+2222 0.66 0.42 +58.93 <0.25 <0.18
J1102+2239 0.65 0.41 +58.60 0.201 ±0.070 0.090 ±0.053 85 ±34
J1110+3653 0.50 0.41 +84.14 0.072 ±0.012 0.057 ±0.020 134 ±20
J1114+3241 0.55 0.44 +66.94 0.074 ±0.004 0.065 ±0.004 103 ±20
J1121+5351 0.51 0.45 −76.04 0.261 ±0.035 0.141 ±0.072 156 ±16
J1138+3653 0.53 0.46 +64.17 0.158 ±0.005 0.049 ±0.021 127 ±3
J1146+3236 0.53 0.43 +60.65 0.061 ±0.005 0.040 ±0.006 37 ±12
J1159+2838 0.52 0.42 +85.32 0.126 ±0.039 0.103 ±0.075 62 ±77
J1203+4431 0.43 0.41 +42.41 0.805 ±0.055 0.260 ±0.037 67 ±2
J1209+3217 0.33 0.30 +44.69 0.139 ±0.038 0.068 ±0.050 122 ±67
J1215+5442 0.46 0.41 +45.18 0.184 ±0.075 0.101 ±0.068 88 ±42
J1218+2948 0.52 0.43 +85.15 0.302 ±0.011 0.234 ±0.017 8 ±10
J1227+3214 0.51 0.42 +87.18 0.188 ±0.025 0.094 ±0.042 30 ±15
J1238+3942 0.43 0.41 +70.94 <0.06 <0.03
J1242+3317 0.50 0.38 +83.17 0.505 ±0.019 0.161 ±0.019 65 ±4
J1246+0222 0.56 0.45 −44.26 0.464 ±0.063 0.251 ±0.086 177 ±15
J1246+0238 0.55 0.41 −35.07
J1302+1624 0.45 0.40 −54.67 0.216 ±0.021 0.173 ±0.024 153 ±22
J1305+5116 1.70 0.44 +51.86 0.146 ±0.799 0.058 ±0.110 52 ±1
J1317+6010 1.13 0.49 +58.10 0.462 ±0.119 0.380 ±0.134 82 ±66
J1333+4141 2.30 1.25 +56.87 0.399 ±0.306 0.041 ±0.264 27 ±30
J1337+2423 1.24 0.47 +62.17 0.155 ±0.044 0.065 ±0.011 67 ±14
J1346+3121 1.06 0.43 +63.78 0.187 ±0.154 0.068 ±0.034 55 ±11
J1348+2622 1.31 0.42 +60.44 0.438 ±0.221 0.164 ±0.035 58 ±5
J1355+5612 1.18 0.58 +64.91 <0.27 <0.11
J1358+2658 1.31 0.41 +60.51 <0.75 <0.11
J1402+2159 1.74 0.42 +58.57
J1421+2824 1.31 0.42 +60.47 0.239 ±0.019 0.068 ±0.003 63 ±1
J1443+4725 0.81 0.42 +68.47 0.102 ±0.008 0.072 ±0.015 120 ±15
J1505+0326 0.42 0.33 −58.68 0.043 ±0.001 0.018 ±0.005 179 ±4
J1536+5433 0.69 0.43 +81.60 0.350 ±0.069 0.116 ±0.073 86 ±11
J1537+4942 0.72 0.43 +75.89
J1548+3511 1.56 0.43 +61.87 0.128 ±0.008 0.054 ±0.001 54 ±2
J1555+1911 0.78 0.43 −70.92 1.040 ±0.230 0.960 ±0.270 178 ±71
J1559+3501 1.47 0.41 +59.78 0.987 ±0.362 0.543 ±0.137 68 ±35
J1612+4219 1.00 0.42 +56.70 <1.4 <0.38
J1629+4007 1.20 0.40 +62.18 0.063 ±0.010 0.017 ±0.002 60 ±3
J1633+4718 0.76 0.40 +73.97 0.091 ±0.005 0.056 ±0.001 76 ±3
J1634+4809 0.79 0.40 +72.76 0.149 ±0.022 0.056 ±0.026 108 ±13
J1703+4540 0.77 0.41 +80.66 0.228 ±0.006 0.103 ±0.002 82 ±1
J1709+2348 0.90 0.40 −65.79
J1713+3523 0.74 0.37 -73.62 0.151 ±0.022 0.106 ±0.006 107 ±15
J2242+2943 0.53 0.46 +50.45 0.655 ±0.048 0.213 ±0.067 174 ±4
J2314+2243 0.68 0.44 +43.11 0.327 ±0.005 0.098 ±0.005 31 ±1
Notes. Columns: (1) short name; (2) beam major axis (arcsec); (3) beam minor axis (arcsec); (4) beam position angle (degrees); (5) core major
axis deconvolved from beam (arcsec); (6) core minor axis deconvolved from beam (arcsec); (7) core position angle (degrees).
14
M. Berton et al.: NLS1s with JVLA
Table A.4. Flux densities, luminosities and brightness temperature of the sources.
Short name rms Sint SplogLint logLplogLdi f f logTb
J0006+2012 10 3.25 ±0.04 3.16 ±0.01 38.42 ±0.01 38.41 ±0.01 36.88 ±0.26 4.62
J0100-0200 10 3.58 ±0.04 3.49 ±0.02 40.47 ±0.01 40.46 ±0.01 38.86 ±0.32 4.72
J0146-0040 10 0.07 ±0.02 0.07 ±0.01 37.95 ±0.12 37.94 ±0.06 36.40 ±0.89 1.90
J0347+0105 15 12.67 ±0.08 8.80 ±0.07 39.17 ±0.01 39.01 ±0.01 38.66 ±0.02 4.00
J0629-0545 12 14.59 ±0.04 12.47 ±0.01 40.43 ±0.01 40.36 ±0.01 39.59 ±0.01 4.23
J0632+6340 10 2.94 ±0.02 1.77 ±0.03 37.76 ±0.01 37.54 ±0.01 37.36 ±0.02 3.34
J0706+3901 13 2.22 ±0.05 1.77 ±0.02 39.33 ±0.01 39.23 ±0.01 38.63 ±0.07 2.99
J0713+3820 12 3.18 ±0.05 2.29 ±0.02 39.82 ±0.01 39.68 ±0.01 39.27 ±0.04 3.09
J0744+5149 10 2.58 ±0.04 2.49 ±0.01 40.98 ±0.01 40.97 ±0.01 39.53 ±0.22 4.53
J0752+2617 12 0.21 ±0.04 0.21 ±0.02 38.19 ±0.09 38.17 ±0.03 36.64 ±0.36 2.03
J0758+3920 18 3.92 ±0.10 2.04 ±0.03 39.68 ±0.01 39.39 ±0.01 39.36 ±0.03 2.47
J0804+3853 11 0.83 ±0.04 0.37 ±0.02 39.69 ±0.02 39.33 ±0.03 39.43 ±0.05 2.14
J0806+7248 10 11.79 ±0.05 11.12 ±0.01 40.17 ±0.01 40.15 ±0.01 38.93 ±0.04 4.69
J0814+5609 10 29.59 ±0.06 25.94 ±0.01 42.19 ±0.01 42.13 ±0.01 41.28 ±0.01 6.05
J0849+5108 35 222.09 ±0.17 219.82 ±0.06 43.21 ±0.01 43.20 ±0.01 41.22 ±0.04 7.11
J0850+4626 11 10.44 ±0.04 10.27 ±0.02 41.77 ±0.01 41.76 ±0.01 39.98 ±0.15 5.50
J0902+0443 13 102.09 ±0.04 101.51 ±0.04 42.77 ±0.01 42.77 ±0.01 40.53 ±0.06 6.70
J0913+3658 11 0.31 ±0.04 0.28 ±0.09 38.66 ±0.06 38.61 ±0.15 37.74 ±1.51 2.52
J0925+5217 11 3.48 ±0.11 1.72 ±0.02 38.72 ±0.01 38.42 ±0.01 38.42 ±0.03 3.35
J0926+1244 12 3.31 ±0.04 2.82 ±0.02 38.52 ±0.01 38.45 ±0.01 37.70 ±0.06 4.05
J0937+3658 12 1.08 ±0.04 0.80 ±0.01 39.71 ±0.02 39.58 ±0.01 39.11 ±0.08 2.64
J0945+1915 11 5.91 ±0.04 5.67 ±0.03 40.90 ±0.01 40.88 ±0.01 39.52 ±0.13 4.74
J0948+5029 15 2.05 ±0.05 1.97 ±0.02 38.91 ±0.01 38.89 ±0.01 37.52 ±0.36 4.34
J0952-0136 11 22.77 ±0.08 20.59 ±0.06 39.04 ±0.01 38.99 ±0.01 38.02 ±0.03 4.92
J0957+2433 10 0.23 ±0.03 0.23 ±0.01 38.32 ±0.06 38.31 ±0.01 36.73 ±2.34 2.28
J1031+4234 10 5.43 ±0.04 5.29 ±0.01 41.14 ±0.01 41.13 ±0.01 39.55 ±0.15 5.34
J1034+3928 10 8.15 ±0.10 7.13 ±0.01 39.24 ±0.01 39.18 ±0.01 38.34 ±0.05 4.72
J1037+0036 11 20.41 ±0.04 20.32 ±0.01 42.19 ±0.01 42.19 ±0.01 39.83 ±0.26 6.43
J1038+4227 10 6.35 ±0.15 1.96 ±0.01 40.67 ±0.01 40.16 ±0.01 40.51 ±0.02 4.03
J1047+4725 33 374.50 ±0.25 207.8 ±3.30 43.77 ±0.01 43.51 ±0.01 43.42 ±0.01 5.50
J1048+2222 10 0.30 ±0.03 0.28 ±0.01 39.75 ±0.05 39.72 ±0.02 38.59 ±0.87 2.76
J1102+2239 15 0.75 ±0.07 0.70 ±0.01 40.47 ±0.04 40.44 ±0.01 39.35 ±0.60 3.57
J1110+3653 10 8.95 ±0.05 7.85 ±0.02 41.89 ±0.01 41.83 ±0.01 40.98 ±0.03 5.32
J1114+3241 10 20.98 ±0.04 20.55 ±0.01 41.04 ±0.01 41.03 ±0.01 39.35 ±0.05 5.53
J1121+5351 11 1.24 ±0.04 1.04 ±0.02 39.25 ±0.01 39.17 ±0.01 38.45 ±0.12 3.32
J1138+3653 10 4.68 ±0.03 4.42 ±0.01 41.02 ±0.01 41.00 ±0.01 39.77 ±0.07 4.71
J1146+3236 11 18.79 ±0.04 18.59 ±0.01 41.90 ±0.01 41.89 ±0.01 39.94 ±0.11 5.87
J1159+2838 10 0.86 ±0.03 0.81 ±0.01 39.76 ±0.02 39.74 ±0.01 38.51 ±0.36 3.70
J1203+4431 12 6.35 ±0.17 1.85 ±0.02 36.46 ±0.01 35.93 ±0.01 36.31 ±0.02 2.77
J1209+3217 13 0.70 ±0.03 0.62 ±0.02 39.31 ±0.02 39.26 ±0.01 38.35 ±0.29 3.70
J1215+5442 10 0.64 ±0.02 0.57 ±0.02 39.30 ±0.01 39.25 ±0.01 38.34 ±0.25 3.37
J1218+2948 9 14.78 ±0.05 11.01 ±0.09 38.47 ±0.01 38.34 ±0.01 37.87 ±0.02 4.02
J1227+3214 12 3.41 ±0.05 3.08 ±0.04 39.94 ±0.01 39.90 ±0.01 38.92 ±0.11 4.12
J1238+3942 13 17.06 ±0.06 17.04 ±0.03 42.16 ±0.01 42.16 ±0.01 39.33 ±1.56 6.04
J1242+3317 12 2.35 ±0.04 1.40 ±0.01 38.74 ±0.01 38.51 ±0.01 38.35 ±0.02 3.08
J1246+0222 11 0.70 ±0.03 0.46 ±0.01 38.31 ±0.02 38.12 ±0.01 37.84 ±0.08 2.44
J1246+0238 12 20.33 ±0.04 19.66 ±0.01 41.69 ±0.01 41.67 ±0.01 40.20 ±0.03 5.36
J1302+1624 11 14.18 ±0.19 3.32 ±0.04 39.91 ±0.01 39.28 ±0.01 39.80 ±0.01 3.80
J1305+5116 13 53.80 ±0.07 34.20 ±0.01 42.91 ±0.01 42.71 ±0.01 42.47 ±0.01 5.68
J1317+6010 11 0.89 ±0.04 0.65 ±0.02 39.42 ±0.02 39.28 ±0.01 38.86 ±0.11 2.45
J1333+4141 14 0.92 ±0.05 0.90 ±0.02 39.85 ±0.02 39.84 ±0.01 38.21 ±1.41 3.65
J1337+2423 13 10.71 ±0.04 9.83 ±0.01 40.26 ±0.01 40.23 ±0.01 39.18 ±0.03 4.86
J1346+3121 12 4.48 ±0.02 4.48 ±0.01 40.63 ±0.01 40.63 ±0.01 4.47
J1348+2622 12 0.43 ±0.02 0.40 ±0.01 40.84 ±0.02 40.80 ±0.02 39.76 ±0.34 2.85
J1355+5612 12 2.06 ±0.05 1.99 ±0.02 39.67 ±0.01 39.65 ±0.01 38.15 ±0.49 3.70
J1358+2658 12 0.60 ±0.03 0.52 ±0.01 40.05 ±0.02 39.99 ±0.01 39.16 ±0.22 2.75
J1402+2159 12 0.40 ±0.02 0.32 ±0.01 38.34 ±0.02 38.24 ±0.01 37.67 ±0.15 2.00
J1421+2824 11 26.35 ±0.05 25.59 ±0.04 42.20 ±0.01 42.18 ±0.01 40.66 ±0.05 5.21
J1443+4725 13 83.24 ±0.08 80.91 ±0.09 42.98 ±0.01 42.97 ±0.01 41.43 ±0.03 6.10
J1505+0326 37 403.28 ±0.14 399.46 ±0.11 43.09 ±0.01 43.09 ±0.01 41.07 ±0.03 7.68
J1536+5433 11 0.52 ±0.03 0.44 ±0.01 37.98 ±0.03 37.92 ±0.01 37.13 ±0.29 2.88
J1537+4942 10 0.84 ±0.03 0.84 ±0.01 40.09 ±0.02 40.09 ±0.01 2.89
J1555+1911 11 0.50 ±0.03 0.12 ±0.01 37.85 ±0.03 37.23 ±0.05 37.73 ±0.05 0.92
J1559+3501 12 1.36 ±0.03 0.49 ±0.03 38.19 ±0.01 37.75 ±0.02 38.00 ±0.03 1.80
J1548+3511 12 64.22 ±0.08 63.54 ±0.01 42.46 ±0.01 42.46 ±0.01 40.49 ±0.06 5.96
J1612+4219 39 0.87 ±0.13 0.34 ±0.05 39.86 ±0.06 39.45 ±0.06 39.65 ±0.14 3.28
J1629+4007 10 42.39 ±0.05 42.29 ±0.01 41.71 ±0.01 41.70 ±0.01 39.06 ±0.29 3.53
J1633+4718 9 25.80 ±0.06 24.20 ±0.01 40.67 ±0.01 40.64 ±0.01 39.46 ±0.02 5.55
J1634+4809 10 5.42 ±0.04 5.20 ±0.02 41.42 ±0.01 41.40 ±0.01 40.03 ±0.12 4.79
J1703+4540 11 34.9 ±0.05 32.46 ±0.05 40.20 ±0.01 40.16 ±0.01 39.04 ±0.02 4.99
J1713+3523 13 3.91 ±0.03 3.67 ±0.01 39.54 ±0.01 39.51 ±0.01 38.33 ±0.09 4.22
J1709+2348 12 0.35 ±0.02 0.35 ±0.01 39.55 ±0.03 39.55 ±0.01 2.76
J2242+2943 13 10.40 ±0.06 5.68 ±0.02 38.88 ±0.01 38.62 ±0.01 38.54 ±0.01 3.44
J2314+2243 11 7.38 ±0.05 6.46 ±0.01 40.48 ±0.01 40.42 ±0.01 39.58 ±0.03 4.20
Notes. Columns: (1) short name; (2) map rms (µJy beam−1); (3) integrated flux (mJy); (4) peak flux (mJy beam−1); (5) logarithm of the integrated
luminosity (erg s−1); (6) logarithm of the peak luminosity (erg s−1); (7) logarithm of the diffuse luminosity (erg s−1); (8) logarithm of the brightness
temperature (K).
15
M. Berton et al.: NLS1s with JVLA
tent with a flat-spectrum object, the in-band spectral indexes re-
veal that it might be a steep-spectrum source. The map shown
in Fig. C.1 seems to show an unresolved core with a size of
307×238 pc. It is not clear whether the faint emission located on
the west side of the core is real or just noise. Given its uncertain
nature, this source would likely require a follow-up at higher res-
olution. Because of its compact size and steep spectrum it might
be classified as a low-power CSS. Its luminosity is indeed lower
than classical CSS sources (O’Dea 1998), but close to another
example of NLS1 classified as CSS, J1432+3014 (Caccianiga
et al. 2014, 2017).
B.3. J0146−0040
2MASX J01464481-0040426 is a radio-quiet NLS1, that in our
map (Fig. C.2) shows only an unresolved core whose size we
could not determine. Its broad-band spectral index is very steep,
since the source is clearly visible in the NVSS survey with a flux
of 8.7 mJy, while it is barely detected at 6σin our survey (to-
tal flux 0.07 mJy). Moreover, J0146−0040 is not detected at 4.7
GHz, while it is clearly visible at 5.7 GHz. This could be a sign
of a minimum in the spectrum around 5 GHz, and of an inverted
spectrum going to higher frequencies. Despite the inverted spec-
trum, the source has not detection at high frequency (37 GHz).
B.4. J0347+0105
IRAS 03450+0055 is a radio-quiet NLS1 associated with a water
maser, often observed in NLS1s Tarchi et al. (2011). The source
was already studied at 8.4 GHz with the VLA-A by Thean et al.
(2000), who found a flux of 6.8 mJy and an unresolved core,
while it was not detected neither through VLBI observations at
22 GHz nor at 37 GHz. In our map (Fig. C.2) the source seems to
show some diffuse emission, particularly extended ∼200 (1.2 kpc)
both South (PA∼188◦) and East (PA∼81◦) of the core. The map
noise is higher with respect to the rest of the sample, possibly
because of the lack of four antennas during the observations.
The core size deconvolved from the beam is 204×115 pc. It is
worth noting that the broad- and in-band spectral indexes are not
in agreement, possibly indicating some variability in this object.
B.5. J0629−0545
IRAS 06269-0543 is classified as a steep-spectrum radio-loud
NLS1, and was observed with the VLA-A at 8.4 GHz by Moran
(2000). This source was detected in the NVSS, but it is not
present in the FIRST survey. The source is not centered on the
NVSS coordinates, but it is found within the error bars. The map
(Fig. C.3), indeed, shows two evident components, separated by
∼2.4 kpc, in perfect agreement with Moran (2000) results. The
south-western component is the brightest and the closest to the
NVSS coordinates, with a peak flux of 12.47 mJy and a spec-
tral index of 0.14±0.01. The north-eastern component (PA∼73◦
with respect to the other component) has instead a flux of 0.42
mJy, and an inverted spectral index (-0.03 ±0.04). In Moran
(2000) the north-eastern component is instead brighter than the
other, with a peak of 0.81 mJy/beam. This might indicate that
the north-eastern source has a strongly inverted spectrum, while
the south-western component has a steeper slope. It is not clear
which one of these two components is the source core.
B.6. J0632+6340
UGC 3478 is a radio-quiet NLS1. It was previously studied by
Kinney et al. (2000) and Schmitt et al. (2001) at 8.4 GHz, find-
ing an unresolved radio structure with a scale of 25 pc and a
flux of 1.4 mJy. Our map (Fig. C.3) reveal an extended struc-
ture on larger scales, with emission diffuse for ∼0.6 kpc both
north and south of the unresolved core, roughly aligned along
PA∼30◦. The core has a deconvolved size of 66×58 pc. Both the
latter and the integrated emission have a steep spectrum, and the
broad-band index is even steeper.
B.7. J0706+3901
FBQS J0706+3901 is a bona-fide F-NLS1s by Foschini et al.
(2015). Our measurements instead indicate that this object is a
steep-spectrum radio-loud NLS1, since all of its spectral indexes
are larger than 0.5. The map (Fig. C.4) shows an unresolved core,
with an approximate size of 800×400 pc, and an intermediate
morphology, with a significant diffuse emission around the core.
Since it is compact and it has a steep radio spectrum, but a rela-
tively low luminosity, it is classifiable as a low-luminosity CSS.
B.8. J0713+3820
FBQS J0713+3820 was classified as F source by Foschini et al.
(2015), with a spectral index of 0.58±0.12 measured at frequen-
cies below 1.4 GHz. Our observations seem instead to indicate
that the index becomes steeper at higher frequencies, in a similar
fashion to CSS objects. The source indeed was not detected nei-
ther at 22 nor at 37 GHz. The map (Fig. C.4) indicates that the
radio emission is compact, with a core size of 1.16×0.59 kpc.
As other RLNLS1s, J0713+3820 likely belongs to the class of
low-luminosity CSS.
B.9. J0744+5149
Little is known about NVSS J074402+514917, which was in-
cluded bona-fide in Foschini et al. (2015) F sample. However, all
of its spectral index are in agreement within the error bars, and
indicate a rather steep radio spectrum, αν∼1.2, consistent with
the non-detection at 22 GHz. The map (Fig. C.5) shows only an
unresolved core with a size of 0.7×0.3 kpc. Its total luminos-
ity is approximately 1041 erg s−1, which is higher with respect
to other radio-loud NLS1s, and comparable to that of the CSS-
NLS1 J1432+3014 (Caccianiga et al. 2015). A strong ongoing
star formation (300 Myr−1) was found investigating the WISE
colors of this object (Caccianiga et al. 2015). The q22 ratio in
this source is 0.47, possibly indicating that the contribution of
star formation is not the main component of the radio emission.
B.10. J0752+2617
Also known as FBQS J0752+2617, it is classified as a radio-
quiet NLS1 and detected only at a 12σlevel. The map of Fig. C.5
shows only an unresolved core whose size could not be deter-
mined. The spectral indexes seem all to point out that the source
has a fairly steep spectrum, with ανlarger than 1.
B.11. J0758+3920
B3 0754+394 is a radio-loud NLS1 which showed a steep-
spectrum below 1.4 GHz (Berton et al. 2015). All of our mea-
16
M. Berton et al.: NLS1s with JVLA
surements are consistent with this classification. The lack of
strong variability found by Sergeev et al. (2007) in a reverbera-
tion mapping campaign is also supportive of its unbeamed emis-
sion. In the map shown in Fig. C.6 the source do not show large
scale structure, with a core size of 2.2×0.7 kpc, but a large frac-
tion of its flux from diffuse emission outside the core. At higher
frequencies the source was detected neither at 22 GHz, nor at 37
GHz.
B.12. J0804+3853
FBQS J0804+3853 if one of the bona-fide F sources. Its broad-
and in-band spectral indexes however indicate that it should be
classified as a S source. The source, as expected from its spec-
trum, is not detected at 37 GHz. The map (Fig. C.6) shows
a moderate extension of the contours in the East direction
(PA∼113◦), and a deconvolved core size of 2.1×1.3 kpc. This
object has a strong star formation rate of about 89 Myr−1and a
high q22, 1.48, suggesting that the majority of the radio emission
in such object comes from starburst. The brightness temperature
of this object, 138 K, is one of the lowest in the sample, in agree-
ment with the starburst-dominated radio emission.
B.13. J0806+7248
RGB J0806+728 was classified as an S source given its steep
broad-band index Berton et al. (2015). However, both core and
integrated spectral indexes we measured are flat. This might be
interpreted as a sign of variability, moving the classification from
S to F source. The source was indeed already observed at 5 GHz,
and showed a flux of 20 mJy (Doi et al. 2007), two times larger
than our measurement. At 1.7 GHz on VLBA scales this source
shows a diffuse morphology extended up to 100 pc from the
core, while it appears as two sided for VLBA at 8.6 GHz (Doi
et al. 2011). Our map (Fig. C.7) do not show extended emis-
sion, which is clearly on smaller scales, but we find a significant
diffuse emission around the unresolved core, whose size is ap-
proximately 250×200 pc. The source was not detected at high
frequency (22 and 37 GHz).
B.14. J0814+5609
SDSS J081432.11+560956.6 was classified as a F source by
Foschini et al. (2015), with a spectral index below 1.4 GHz of
0.38±0.01. The map (Fig. C.7) clearly shows that the source
has a large scale extended emission directed toward South-East.
The extended emission, accounting for ∼12% of the total flux,
shows a bright spot at PA∼119◦, with a peak of 1.58±0.02 mJy,
at 3.4 arcsec (∼21 kpc), while the total emission on the map
reaches a distance of 5.3 arcsec (∼33 kpc), where it shows an
edge-brightening at PA∼137◦. The deconvolved size of the core
is 0.5×0.2 kpc. On VLBA scales (Gu et al. 2015) the structures
we observed are resolved-out, but the source still shows an elon-
gated structure at 2, 5 and 8 GHz, extended toward East just like
on our map. The in-band spectral indexes are flat, showing that
both the core and the secondary bright spot have a flat spectrum.
The broad-band index instead is slightly steeper. This might be
due both to the extended emission, but also to variability. Doi
et al. (2016) found a VLBI flux of 117 mJy at 22 GHz, sign of
strong variability in the core. Conversely, despite multiple obser-
vations, the object was not detected at 37 GHz.
B.15. J0849+5108
SBS J0846+513 is one of the brightest γ-ray emitting NLS1, that
on VLBA scales at 5 GHz and higher frequencies shows a core-
jet morphology and superluminal motion (up to 8c, D’Ammando
et al. 2012). It was also monitored at multiple frequencies,
showing a rather strong variability both in flux and polarization
(Maune et al. 2014; Angelakis et al. 2015). It is a flat spectrum
source, and as expected it was detected both at 22 GHz (flux
454 mJy), and at 37 GHz (highest measured flux of 1.18 Jy).
The source on kpc scales has a compact morphology (Fig. C.8),
with a core size 320×215 pc. The brightness temperature calcu-
lated from our data, although relatively low because of the large
beam size of the VLA, is the second highest of our sample, with
∼1.3×107K.
B.16. J0850+4626
SDSS J085001.16+462600.5 was classified as S source accord-
ing to low frequency (ν < 1.4 GHz) data. Our spectral indexes
however seem to be consistent with a flat-spectrum source. The
source, however, is detected neither at 22 GHz, nor at 37 GHz.
The object appears as an unresolved core (Fig. C.8), with a
deconvolved size of 375×350 pc. This source was studied on
VLBA scales by Gu et al. (2015), who found a compact mor-
phology. The flux they measured at 5 GHz (11 mJy) is slightly
larger than our value, possibly indicating a relatively small scale
variability.
B.17. J0902+0443
SDSS J090227.16+044309.5 was included in the F sample by
Foschini et al. (2015), showing a broad-band spectral index of
0.07±0.01. Our results confirm this classification. The source is
one of the few showing a flux larger than 100 mJy, with a lu-
minosity of ∼6×1042 erg s−1. A significant flux variability (∼10
mJy) was found by previous measurements at 5 GHz with the
NRAO 91m telescope (Becker et al. 1991; Griffith et al. 1995;
Yuan et al. 2008), and is also consistent with our result. Our
map, shown in Fig. C.9 shows a partially resolved structure of
∼6.5 kpc at PA∼142◦, in the South-East direction. An elongated
structure was already visible on VLBA scales, although its direc-
tion appears to be slightly different (Gu et al. 2015). The source
was detected at 22 GHz, but not at 37 GHz. This source has a
very high star formation rate (∼500 Myr−1), which however is
not strongly contributing to the radio emission, as suggesting by
the q22 =-0.65.
B.18. J0913+3658
RX J0913.2+3658 is a radio-quiet object, already observed by
the FIRST survey with a flux of approximately 1 mJy. Our ob-
servation is the first carried out at 5 GHz, and it revealed a rather
steep spectrum and a low brightness temperature. In the map
shown in Fig. C.9 the source shows a significant diffuse emis-
sion outside of an unresolved core whose size is 680×350 pc.
B.19. J0925+5217
Mrk 110 is a well studied radio-quiet NLS1, detected by NVSS
and often studied at 5 GHz, finding fluxes consistent with our
measurements (Nelson 2000; Wu & Cao 2005; Kataoka et al.
2011). Its core has a rather flat spectral index, while the total
flux is steep. At VLBA scales, this object shows only a point-like
17
M. Berton et al.: NLS1s with JVLA
core of 1.1 mJy (Doi et al. 2013). Our map (Fig. C.10) shows an
extended diffuse emission toward North, West and South. In par-
ticular, at PA 209◦the emission reaches a distance of 5.8 arcsec
(11.4 kpc), while a bright spot can be found at PA 16◦at 2.3 arc-
sec (4.5 kpc). The emission in the North direction was already
detected by Kukula et al. (1998). The diffuse flux represents ap-
proximately 51% of the source total emission. The unresolved
core in our image has a size of 200×130 pc.
B.20. J0926+1244
Mrk 705 is a radio-quiet NLS1, that in our analysis shows steep
spectral indexes. There is a nearby radio source at 30 arcsec at
PA 175◦, SDSS J092603.50+124333.6, with an FR II morphol-
ogy, a flux of ∼10 mJy, and the optical spectrum of an elliptical
galaxy. The main source on VLBA scales showed a possible lin-
ear structure of 26 pc extending toward East (Doi et al. 2013),
while previous VLA-A observations at 8.46 GHz showed only a
compact source (Schmitt et al. 2001). Fig. C.10 also shows a rel-
atively bright (76 µJy) spot at 1.7 arcsec (∼1 kpc) at PA 67◦, and
a second one (73 µJy) at 1.1 arcsec (0.6 kpc) at PA 38◦. The core
has a size of 96×60 pc. The flux outside the central beam rep-
resents approximately 15% of the total emission, making it an
intermediate morphology source according to our classification.
B.21. J0937+3615
FBQS J0937+3615 is one of the bona-fide F sources, which
shows a fairly high star formation rate that can significantly
contribute to the radio emission (83 Myr−1, Caccianiga et al.
2015). Our measurements indicate that both the in- and broad-
band spectral indexes are steep. This object, shown in Fig. C.11,
has an unresolved core whose size is 1.4×0.9 kpc, and its flux
fairly is spreaded out, with peak flux representing 74% of the
total emission and a very low brightness temperature (436 K).
It has not been detected at 37 GHz. These properties seem to
suggest that the source radio emission is dominated by star for-
mation.
B.22. J0945+1915
SDSS J094529.23+191548.8 is a bona-fide F source, also show-
ing a high star formation rate (138 Myr−1, Caccianiga et al.
2015). The spectral indexes are all steep, therefore this source
should be reclassified as S. Fig. C.11 shows a partially resolved
structure at PA 314◦extended for ∼1.1 arcsec (4.7 kpc), but the
diffuse emission is rather low. The core is unresolved, and its
deconvolved size is 490×330 pc. It was not detected at 37 GHz.
Given its luminosity of ∼8×1041 erg s−1, it might be classified as
a classical CSS.
B.23. J0948+5029
Mrk 124 is a radio-quiet NLS1 which was never observed before
at 5 GHz. All the spectral indexes are consistent with a steep
spectrum within the error bars. The source in the map (Fig. C.12)
appears as an unresolved compact core, whose deconvolved size
is 160×50 pc.
B.24. J0952-0136
Mrk 1239 is a NLS1 which has been classified as radio-quiet
(Doi et al. 2015) or barely radio-loud (Berton et al. 2015). This
object was studied repeatedly in radio, finding extended emis-
sion reminiscent of an FR I radio galaxy (Doi et al. 2013, 2015).
Comparing VLA and VLBA observations, Orienti & Prieto
(2010) found that almost 80% of the VLA (at 15 GHz) flux was
missing on VLBA scales, suggesting the presence of a very sig-
nificant extended emission. Our map, shown in Fig. C.12, reveals
indeed extended emission everywhere around the core, which
was the only component visible in 15 GHz VLA images. The
largest extension is measured at PA 212◦, at a projected distance
of 3.7 arcsec (1.5 kpc). The unresolved core has a size of 84×33
pc, and it shows a flat in-band spectrum. The total emission also
has a flat spectrum, but it is dominated by the core, which rep-
resents the 90% of the entire flux. The broad-band spectrum is
instead steep between 1.4 and 5 GHz and, as expected from this
slope, the source is not detected at 22 GHz.
B.25. J0957+2433
RX J0957.1+2433 is a radio-quiet NLS1. All of its spectral in-
dexes are steep, and in particular its broad-band index is the sec-
ond steepest of our sample. The map of Fig. C.13 does not show
any structure with the exception of the unresolved core, whose
size could not be calculated because of the source faintness.
B.26. J1031+4234
SDSS J103123.73+423439.3 is classified as an F source, with a
spectral index below 1.4 GHz of -0.40±0.06 (Yuan et al. 2008;
Foschini et al. 2015). Our spectral index measurements point in
a different direction, showing a much steeper broad-band index,
and relatively steep in-band indexes (although close to the 0.5
threshold). This might be an indication of a curved spectrum
peaking at low frequencies, possibly in the MHz range, or of
source variability. The map (Fig. C.13) clearly shows a compact
source, with a deconvolved size lower than 0.6×0.1 kpc and a
luminosity higher than 1041 erg s−1. If the source spectrum is ac-
tually peaked at low frequencies, these properties might indicate
that this object is classifiable as a classical CSS.
B.27. J1034+3928
KUG 1031+398 is a steep-spectrum radio-loud source. While
the broad-band index is clearly in agreement with this classifica-
tion, the in-band indexes are flat, particularly in the core. The ex-
tended emission represents approximately 13% of the total flux,
and it is visible for ∼5 arcsec (4.5 kpc) both East and West of the
source. The unresolved core has a deconvolved size of 100×65
kpc. The source was not detected at 22 GHz with VLBA.
B.28. J1037+0036
SDSS J103727.45+003635.6 is one of the bona-fide F sources.
Our spectral index measurements indicate that its assumption
was correct. The map, shown in Fig. C.14, shows only an un-
resolved core, with a luminosity of 1.5×1042 erg s−1and a de-
convolved size of 370×90 pc. The brightness temperature, above
106K, is one of the highest of the sample. The source is however
too weak to be detected at 22 and 37 GHz.
B.29. J1038+4227
FBQS J1038+4227 is a bona-fide flat-spectrum source.
However, our measurements suggest that this source is instead
18
M. Berton et al.: NLS1s with JVLA
a steep-spectrum object. The map of Fig. C.15 shows an unre-
solved core of size 450×410 pc, and a spreaded-out extended
emission that accounts for 69% of the total flux and is found as
far as 8.4 arcsec from the radio core (∼30 kpc) at PA 313◦. The
source is not detected at 37 GHz.
B.30. J1047+4725
SDSS J104732.68+472532.0 is classified as an F source, and
our in-band indexes confirm this classification. The broad-band
index is steeper than that found by Foschini et al. (2015)
(0.33±0.01), likely as a consequence of variability. The source
has the highest luminosity of our sample, 6×1043 erg s−1, 55%
of which comes from an unresolved core of 3.6×1.2 kpc. The
rest of the flux, as shown in Fig. C.15, is originated in a partially
resolved diffuse emission extended up to 1.3 arcsec (9.5 kpc)
from the nucleus at PA 318◦. Such structure is resolved into a
core-jet system in high resolution images with VLBA at 5 GHz
(Gu et al. 2015). This object is the second farthest in our sample,
at z =0.799. The source was not detected at 22 and 37 GHz,
indicating a possible steepening of the spectrum above 5 GHz.
B.31. J1048+2222
SDSS J104816.57+222238.9 was classified as a F source bona-
fide, but our spectral indexes seem to indicate a steep-spectrum
nature. The map in Fig. C.16 does not show any particular struc-
ture, but an unresolved core whose size is lower than 1.2×0.9
kpc. The source was not detected at 37 GHz.
B.32. J1102+2239
FBQS J1102+2239 was classified as one of the γ-ray emitters
(Foschini 2011), although this property has not been confirmed
(Foschini et al. 2015). The map of Fig. C.16 shows only the
unresolved core with a size of 1.2×0.5 kpc. The core spectral
index, which has never been estimated before, unlike other G
sources indicate a steep in-band spectrum, in agreement with the
broad-band spectrum. The object was not detected at 37 GHz.
The source is characterized by a very high level of star forma-
tion, 302 Myr−1, and it has a q22 parameter of 1.34, which is
characteristic of starburst galaxies (Caccianiga et al. 2015). If the
γ-ray emission were to be confirmed, this would one of the few
examples of γ-ray emitting S-NLS1 (Liao et al. 2015; Komossa
et al. 2015; Berton et al. 2017).
B.33. J1110+3653
SDSS J111005.03+365336.3 is another bona-fide F source,
whose nature is confirmed by the flat in-band spectral indexes.
The broad-band index is steeper, but still consistent with the
flat classification within the error bars. The source (Fig. C.17)
presents an unresolved core whose size is 500×390 pc, and a
diffuse emission extended up to 3.1 arcsec (21 kpc) from the nu-
cleus at PA 156◦that accounts for ∼13% of the total flux. This
diffuse emission was not detected with VLBA at 5 GHz, where
the core flux is 8.8 mJy (Gu et al. 2015). The source was detected
neither at 22 GHz, nor at 37 GHz.
B.34. J1114+3241
B2 1111+32 was classified as S source by Komossa et al. (2006).
However, our spectral indexes indicate instead a flat spectrum.
The broad-band index is also strongly inverted, a behavior ob-
served only in seven of our sources. These indexes strongly sup-
port the presence of a powerful relativistic jet in this object, pos-
sibly connected with the generation of the powerful mildly rela-
tivistic outflows observed in this superluminous infrared galaxy
(Tombesi et al. 2015). The map of Fig. C.17 shows only an un-
resolved core, whose deconvolved size is 230×200 pc.
B.35. J1121+5351
SBS 1118+541 is a radio-quiet NLS1. All of its spectral indexes
might be steep, although they are consistent with a flat behav-
ior within the error bars. The brightness temperature however is
very low (∼2000 K), which seems to favor the steep-spectrum
hypothesis. The map (Fig. C.18) shows only an unresolved core
of size 490×270 pc.
B.36. J1138+3653
SDSS J113824.54+365327.1 was classified as a flat-spectrum
source according to its spectral index 0.50 ±0.09 below 1.4 GHz
(Foschini et al. 2015). Our in-band indexes confirm the classifi-
cation, while the broad-band index indicates a steep-spectrum,
likely because of variability. The unresolved core has a decon-
volved size of 790×245 pc, and it is the only structure visible in
our map (Fig. C.18), and also in the VLBA map at 5 GHz by Gu
et al. (2015). The latter observations found a core flux of 9 mJy,
almost double of our measurement, an indication of significant
variability of the source. Despite this, the source was detected
neither at 22 GHz nor at 37 GHz. Finally, this source shows a
significant amount of star formation (14 Myr−1), which how-
ever does not seem to be relevant when compared to the AGN
activity (Caccianiga et al. 2015).
B.37. J1146+3236
SDSS J114654.28+323652.3 is a flat-spectrum source which
was detected at frequencies below 1.4 GHz (Foschini et al.
2015). Our spectral indexes all confirm the classification, even
suggesting a slightly inverted broad-band radio spectrum. The
source appears essentially as an unresolved core whose decon-
volved size is 360×235 pc. However, some dim diffuse emission
might be present in the map (see Fig. C.19). In particular there
are two significantly brighter regions (6σdetection). The clos-
est one, at 1.4 arcsec (8.2 kpc) at P.A. 130◦, is relatively compact
and has a peak of 68 µJy, while the second one, more diffuse, has
a peak of 97 µJy and a total flux of 433 µJy, and is located at P.A.
154◦4.5 arcsec (26.5 kpc) away from the source core. There are
no nearby sources that can affect the map with their sidelobes.
This source was detected at 22 GHz with a flux of 104 mJy, a
sign of high variability, but not at 37 GHz.
B.38. J1159+2838
FBQS J1159+2838 is one of the bona-fide F sources included in
the Foschini et al. (2015) sample. Our spectral indexes however
led us to classify this object as a S-NLS1. The source appears in
Fig. C.19 as an unresolved core whose deconvolved size is ap-
proximately 430×350 pc. With respect with other similar objects
J1159+2838 seem to have a lower luminosity, 6×1039 erg s−1,
below the S average, while according to Caccianiga et al. (2015)
the star formation is fairly high, 128 Myr−1. This, along with
the low brightness temperature, might indicate that starburst is a
19
M. Berton et al.: NLS1s with JVLA
major source of radio emission in this object, as indicated also
by its q22 ratio (1.39). This source was not detected at 37 GHz.
Given these properties, this object might be classified as a low-
luminosity CSS.
B.39. J1203+4431
NGC 4051 is the closest NLS1, and a radio-quiet source. The
core spectral index is significantly flatter than the integrated flux
and broad-band indexes, possibly because of the presence of
a non-thermal radio source in the nucleus, possibly a jet-base
structure (Giroletti & Panessa 2009). Its core revealed also the
presence of a water-maser, consistent with a nuclear outflow
(Tarchi et al. 2011). Our map of Fig. C.20 shows a large scale
diffuse emission surrounding the unresolved core. The latter has
a size of 33×11 pc. The extended emission in the core is instead
directed approximately at P.A. 240◦, but then it bends toward
South-East forming a sort of horseshoe structure. More diffuse
emission is visible on the other side of the nucleus, at P.A.∼60◦.
The diffuse emission accounts roughly for 61% of the total lu-
minosity of the source. NGC 4051 is detected only because of
its vicinity: its luminosity is indeed the lowest of the sample,
3×1036 erg s−1.
B.40. J1209+3217
RX J1209.7+3217 is a radio-quiet source that appears in the map
(Fig. C.20) with no particular features, and an unresolved core of
350×170 pc. The steep spectral indexes and the low brightness
temperature are typical of radio-quiet sources.
B.41. J1215+5442
SBS 1213+549A is a radio-quiet NLS1 with steep spectral in-
dexes and a low brightness temperature. The map of Fig. C.21
indicates the presence of some weak diffuse emission toward
South-East, at P.A. 154◦, approximately extended for 1.1 arcsec
(3 kpc). The unresolved core has a size of 480×260 pc.
B.42. J1218+2948
Mrk 766 is a well-known NLS1, harboring a strong water maser
which seem to indicate the presence of a jet (Tarchi et al. 2011).
The unresolved core of the source has a size of 80×60 pc, and
it shows a flat spectrum, just like the in-band integrated index.
Only the broad-band spectral index is consistent with a steep
spectrum. Our estimated flux is in good agreement with previ-
ous observation at 5 GHz with the VLA-A (14.5 mJy, Lal et al.
2011). The brightness temperature of ∼10000 K is higher with
respect to other radio-quiet objects. The map of Fig. C.21 shows
a diffuse emission around the source particularly on the North-
East side, and a brighter spot at P.A. 102◦, at 1.6 arcsec (430
pc) from the core. This diffuse emission accounts for ∼26% of
the total flux. This object appears compact on VLBI scale, and it
was not detected at 22 GHz.
B.43. J1227+3214
FBQS J1227+3214 was classified as a flat source according to its
inverted spectral index (-1.04±0.07, Foschini et al. 2015). Albeit
we do not find the same strongly inverted spectrum, our clas-
sification remain consistent with the previous one. The source
map in Fig. C.22 reveals an unresolved core whose deconvolved
size is 450×225 pc, and possibly some diffuse emission in the
North-East direction (PA∼45◦). The star formation in this object
is relatively high, 54 Myr−1as reported by Caccianiga et al.
(2015). The q22 ratio is also fairly high (1.29), possibly suggest-
ing that a significant contribution to radio emission is provided
by starburst. The source was not detected at 37 GHz.
B.44. J1238+3942
SDSS J123852.12+394227.8 is a bona-fide F source, that in
our measurements show a rather inverted radio spectrum both
according to in- and broad-band spectral indexes. The map of
Fig. C.22 shows an unresolved core with a size lower than
400×200 pc. Despite the inverted spectrum, the source was not
detected neither at 22 GHz nor at 37 GHz, possibly indicating a
slope change toward higher frequencies.
B.45. J1242+3317
WAS 61 is a radio-quiet source with steep spectral indexes, not
different from several others Q objects. The source, as seen in the
map of Fig. C.23, is elongated in the East direction (P.A.∼90◦).
This extended emission accounts for approximately 40% of the
source total flux. The unresolved core size is 440×140 pc.
B.46. J1246+0222
PG 1244+026 is a well-known radio-quiet NLS1, that in the map
of Fig. C.23 shows an unresolved core of 440×240 pc that ac-
counts only for 66% of the total emission. Our flux measure-
ment is rather similar to a previous measurement by Sikora et al.
(2007), who found a slightly higher flux of 0.83 mJy. The core
spectral index is uncertain, consistent both with flat and steep
values, while the spectral index of the extended emission seems
to be flat. Conversely, the broad-band index is definitely steep.
However, the brightness temperature is the second lowest of the
sample, 275 K, suggesting that the radio emission might be of
thermal origin.
B.47. J1246+0238
According to Foschini (2011), SDSS J124634.65+023809.0 is
aγ-ray source. The spectral indexes are all flat, as expected
from this kind of source, and in agreement with the index al-
ready measured by Foschini et al. (2015). The source, as shown
in Fig. C.24, appears only as an unresolved core. The same com-
pact core is reported by Gu et al. (2015) at 5 GHz with VLBA
observations. The flux they measured was less than half our
value (8.7 mJy against 19.66 mJy in the core), suggesting that
this source is strongly variable. Despite this, it was not detected
neither at 22 GHz nor at 37 GHz. The star formation is not negli-
gible (68 Myr−1), but the q22 parameter of -0.36 suggests that
it is not the main contributor to the radio emission.
B.48. J1302+1624
Mrk 783 is a NLS1 at the edge of the radio-quiet/radio-loud
threshold. Already studied in detail by Congiu et al. (2017a),
we confirm the results of their analysis. Its in-band integrated
spectral index is the steepest of our entire sample, in agreement
with the hypothesis that the large extended emission visible in
Fig. C.24 is a relic. Interestingly, this faint extended emission
is associated with an ionized region of gas located 35 kpc away
20
M. Berton et al.: NLS1s with JVLA
from the nucleus, a unique case among NLS1s (Congiu et al.
2017b). The source was not detected with VLBA at 22 GHz.
B.49. J1305+5116
SDSS J130522.74+511640.2 was originally classified as an S
source and analyzed by Berton et al. (2015) because of a de-
tection at low frequency (150 MHz, 320 mJy, Yuan et al. 2008)
which allowed the spectral classification. The source was later
discovered to be a γ-ray source (Liao et al. 2015), and the in-
band indexes allow us to change its classification in F-NLS1.
In the map of Fig. C.25 it clearly shows two components sepa-
rated by 1.1 arcsec (8.1 kpc) at P.A. 168◦. It is not certain where
the core is, since both of the components have a flat or inverted
spectrum. However, the North (N) component core accounts for
∼64% of the total flux, while the South (S) component has a
peak of 18.3 mJy beam−1. The NVSS coordinates point on the N
source, but the uncertainty on the declination is fairly large (0.6
arcsec). Gu et al. (2015) detected the same kind of structure at
2.2, 5, and 8.6 GHz with VLBA. At 5 GHz they found however
a flux of 15 mJy, which is less than half the flux we obtained for
the N component only, indicating that there is a large fraction
of diffuse emission which VLBA cannot resolve. The N compo-
nent has a unresolved core whose size is 1.1×0.4 kpc, while the
S component core is 2.8×1.8 kpc large. A possibility is that the
N component is the core, while the S component is the hot-spot
of a radio lobe. The source was not detected both at 22 GHz and
37 GHz.
B.50. J1317+6010
SBS 1315+604 is a radio-quiet NLS1. In the map of Fig. C.25
the source shows no significant structure, and an unresolved core
of 1.1×0.9 kpc. The core has a flat spectrum, while the total
emission is steeper, although still consistent with the flat clas-
sification. The broad-band index instead is steep. The brightness
temperature is extremely low, 282 K, and suggests a possible
thermal origin of the radiation.
B.51. J1333+4141
SDSS J133345.47+414127.7 is one of the bona-fide F sources,
but according to our spectral indexes this source appears to be
steep-spectrum. In Fig. C.26 J1333+4141 is compact, with a de-
convolved core size of 1.4×0.2 kpc. The brightness temperature
is low, ∼4500 K, and star formation appears to be very relevant
in the radio. The q22 parameter is indeed 1.39, and the star for-
mation rate is 148 Myr−1(Caccianiga et al. 2015). It was not
detected at 37 GHz. Because of its properties, it can be consid-
ered as a low-luminosity CSS.
B.52. J1337+2423
IRAS 13349+2438 is a well-studied radio-quiet NLS1. The map
of Fig. C.26 shows an intermediate morphology, with an ex-
tended emission at P.A. 86◦reaching up to ∼2 arcsec (7.1 kpc).
Both the in-band spectral indexes are flat, just like the broad-
band spectral index. The unresolved core has a size of 560×235
pc. The brightness temperature, with respect to other radio-quiet
sources, is high, ∼72000 K. Given these properties, we cannot
rule out that this source harbors a low-power relativistic beamed
jet.
B.53. J1346+3121
SDSS J134634.97+312133.7 is one of the bona-fide F sources,
and our measurements confirm this classification, since all the
spectra are strongly inverted, more than any other source in the
sample. Despite this, this object was not detected yet at 37 GHz.
The map of Fig. C.27 shows no particular features, with a core
of size 720×260 pc and a relatively low brightness temperature
(∼30000 K).
B.54. J1348+2622
SDSS J134834.28+262205.9 is another bona-fide F source,
which we reclassify as steep-spectrum. It is the most distant
source of the sample (z =0.917), and in the map of Fig. C.27
it appears as a compact source with a deconvolved core size
of 3.4×1.3 kpc and some faint diffuse emission toward South
and East. The spectral indexes are all rather steep, of the order
of unity, and the brightness temperature is low, ∼700 K. These
characteristics seem to recall those of sources with high star
formation rates. However, this is in contrast with the result of
Caccianiga et al. (2015), who did not find any sign of strong
starbursts using WISE colors.
B.55. J1355+5612
SBS 1353+564 is a radio-quiet NLS1. The in-band spectral in-
dex of the core is flat, and the same is true for the in-band
index of the integrated emission. The broad-band index is in-
stead steep. We could provide only an upper limit to the decon-
volved core size, which is smaller than 650×265 pc. The map
of Fig. C.28 does not reveal any particular structure beside the
core.
B.56. J1358+2658
SDSS J135845.38+265808.4 was classified bona-fide as F
source by Foschini et al. (2015), but given our measurements we
classified this source as steep-spectrum. Our map in Fig. C.28 re-
veals an unresolved core, whose size is smaller than 3.6×0.5 kpc,
surrounded by a faint diffuse emission that accounts for 14% of
the total flux. This object has a relatively high star formation rate
(130 Myr−1) and a q22 =1.30, suggesting that the contribution
of starbursts is strong in radio.
B.57. J1402+2159
RX J1402.5+2159 is a radio-quiet NLS1. The spectral indexes
indicate a steep-spectrum source, although the in-band index of
the integrated flux is, within the error bars, consistent with a
flat spectrum. The map (Fig. C.29), despite the very elongated
beam, reveals a diffuse emission directed at P.A. 65◦extended
for 4.1 arcsec (5.2 kpc). The diffuse emission accounts for 20%
of the total flux. It is worth noting that within 400 arcsec from
the source there are four other neighbors. One of them is a NVSS
radio source, J140250+220154, with a flux of 24 mJy.
B.58. J1421+2824
SDSS J142114.05+282452.8 was classified as F source accord-
ing to its inverted radio spectrum (-0.20±0.01, Foschini et al.
2015). Our spectral indexes all confirm the same classification,
although none of them is inverted, likely because of the source
21
M. Berton et al.: NLS1s with JVLA
variability. The map of Fig. C.29 shows, outside the core, an
elongated structure extended for 2.8 arcsec (18 kpc) at P.A. 82◦.
The deconvolved core size is 1.5×0.4 kpc. VLBA observations
of this object revealed a partially resolved core-jet structure, with
a flux in very good agreement with our estimate (27 mJy against
26.35), and confirm the flat-spectrum of the source (Gu et al.
2015). Finally, this object was detected at 22 GHz by VLBA
with a flux of 117 mJy, but not at 37 GHz.
B.59. J1443+4725
B3 1441+476 was classified as a S source according to data
found in the literature (e.g. Gregory & Condon 1991; Douglas
et al. 1996; Condon et al. 1998), which suggested a spectral in-
dex between 151 MHz and 5 GHz of ∼0.65. Given the compact
spectrum, its relatively small size and its luminosity (9.5×1042
erg s−1), the source was classified as a CSS. However, our in-
band measurements indicate that the radio spectrum is flat, a
result in good agreement with the detection of γ-ray emission
found in this object (Liao et al. 2015). This might suggest that
the apparent steep spectrum measured in the past was due to
non-simultaneous observations and source variability. In support
of the variability hypothesis, the flux at 5 GHz measured in the
87GB catalog (Gregory & Condon 1991) was 59 mJy, while we
obtained a flux of ∼83 mJy. The different instrument they used
(Green Bank telescope) is not enough to explain this different
flux. On the VLBA scales, this object has a clear one-sided core-
jet morphology (Gu et al. 2015), while in our map (Fig. C.30)
the source is only partially resolved, with an elongated structure
at P.A. 146◦extended for 1.1 arcsec (7.8 kpc). The unresolved
core has instead a deconvolved size of 730×515 pc.
B.60. J1505+0326
SDSS J150506.47+032630.8 is one of the γ-ray emitters, as-
sociated with 3FGL J1505.1+0326 by the Fermi collaboration
(Ackermann et al. 2015). All of its spectral indexes are flat,
and its luminosity is the second highest of the sample, 1.2×1043
erg s−1. The map of Fig. C.30 shows an unresolved core with
a deconvolved size of 230×100 pc and a brightness tempera-
ture 4.8×107K, the highest in the sample, but also a second
source at P.A. 252◦and 2.4 arcsec (13.2 kpc) away from the
source core. This secondary source has a peak flux of 271 µJy
and an integrated flux of 621 µJy, and a rather steep spectral in-
dex in the core, ∼1.2. Given the brightness of the main source,
the noise level is higher than in other maps, therefore we could
not establish whether this secondary source is associated with
J1505+0326, or it is a background object unconnected with it.
However, it is worth noting that a jet-core structure with the
same position angle as the secondary soure was observed at 2.3
GHz with VLBA (). J1505+0326 was detected both at 22 GHz
and at 37 GHz. Flaring events are not uncommon in this object
(e.g. D’Ammando et al. 2016), as proven by past flux VLA-A
measurement at 5 GHz that provided a flux of 926 mJy, twice
as much with respect to our present estimate (Dallacasa et al.
2000).
B.61. J1536+5433
Mrk 486 is a radio-quiet NLS1, detected only by FIRST. The
map of Fig. C.31 shows only an unresolved core with a decon-
volved size of 270×90 pc. The spectral indexes are all steep, even
if the error bars of the in-band indexes do not exclude the pos-
sibility of a flat spectrum. The low brightness temperature (759
K), however, seems to be more consistent with a steep spectrum
of starburst origin.
B.62. J1537+4942
SBS 1536+498 is the most distant radio-quiet NLS1 of the sam-
ple (z =0.280). Fig. C.31 shows only a compact source with
spectral indexes that are consistent with both a flat- and a steep-
spectrum. The broad-band index instead seems to rule out the
steep spectrum, since it is lower than 0.5 even considering the
error bars.
B.63. J1548+3511
SDSS J154817.92+351128.0 was classified as a flat-spectrum
source, and detected below 1.4 GHz. Our in-band indexes con-
firm the classification, while the broad-band index is steep
likely because of variability. Our flux measurement is in agree-
ment with that already carried out by the VLA-A by Laurent-
Muehleisen et al. (1997), who found 60 mJy against our ∼64
mJy. The map of Fig. C.32 shows only a compact source, whose
unresolved core has a deconvolved size of 760×320 pc. On
VLBA scales, instead, this object has a core-jet morphology,
extended in the North-West direction and an inverted-spectrum
bright core (Gu et al. 2015). The source has a flux of 22 mJy at
22 GHz, and it was detected also at 37 GHz with a flux of 340
mJy. Finally, J1548+3511 has a fairly high star formation rate of
151 Myr−1, and a q22 =-0.77. This latter value suggests that
the radio is indeed originated in the relativistic jet.
B.64. J1555+1911
Mrk 291 is a radio-quiet source which in Fig. C.32 shows only
a spreaded-out emission extended for ∼2 arcsec (1.4 kpc) with
a steep spectrum and a very low brightness temperature of ∼8
K. These properties might indicate that its radio emission has a
thermal origin.
B.65. J1559+3501
Mrk 493 is a radio-quiet NLS1 which shows steep spectral
indexes and a low brightness temperature (63 K). The map
(Fig. C.33) shows a diffuse emission surrounding in every di-
rection the unresolved core, which has a deconvolved size of
610×335 pc.
B.66. J1612+4219
SDSS J161259.83+421940.3 is one of the bona-fide NLS1 clas-
sified as F. Our spectral indexes seem to be in agreement with
this classification, but the presence of a strong nearby source in
the visibilities hampered our analysis, introducing large errors in
our measurements. Indeed, in the map of Fig. C.33, the source
morphology cannot be clearly understood, even if it might be
somewhat extended. This object was detected at 37 GHz with a
flux of 460 mJy. The star formation rate of this object was esti-
mated as 224 Myr−1, with an associated q22 =1.32. Starburst
therefore might strongly contribute to the radio emission of this
object.
22
M. Berton et al.: NLS1s with JVLA
B.67. J1629+4007
SDSS J162901.30+400759.9 was classified as F source, hav-
ing a strongly inverted spectrum between 1.4 and 5 GHz (-
0.68±0.02, Foschini et al. 2015). Our spectral indexes confirmed
this classification. The map of this source in Fig. C.34 shows a
compact structure with an unresolved core of 260×70 pc, and a
secondary, faint source located 2.6 arcsec (10.8 kpc) away from
the core at P.A. 93◦. This second source has a flux density peak
of 78 mJy beam−1, and it is not clear whether it is related with
J1629+4007 or not. The main source was detected both at 22
GHz with VLBI with 145 mJy, and at 37 GHz with 350 mJy.
According to Caccianiga et al. (2015), J1629+4007 has a star
formation rate of 25 Myr−1and a q22 index of 0.29, suggest-
ing that the bulk of the radio emission is of non-thermal origin.
B.68. J1633+4718
SDSS J163323.58+471858.9 was classified as F source, and
our in-band indexes are in agreement with such classification.
The broad-band index is instead steep, but variability is defi-
nitely present, since while our flux estimate is 26 mJy, Laurent-
Muehleisen et al. (1997) report instead 30 mJy at 5 GHz. The
map shows an unresolved core with a deconvolved size of
190×120 pc, and a second fainter source located at P.A. 352◦3.8
arcsec (8 kpc) away from the core. Diffuse emission is present
between these two bright spots, suggesting that they belong to
the same structure, and indicating a core-jet morphology. The
second structure has an integrated flux of 780 µJy, and an in-
band spectral index (integrated) of 0.4. This secondary compo-
nent accounts for the 6% of the total flux, and it was not seen
with VLBA either by Doi et al. (2011) at 1.7 GHz or by Gu
& Chen (2010) at 5 GHz, likely because it was resolved out.
The star formation rate of this object is 68 Myr−1, with q22
=0.23. These parameters seem to indicate that, although strong,
starburst are not decisive in the radio emission. At 22 GHz the
source was detected showing a flux of 163 mJy, while it was not
detected at 37 GHz.
B.69. J1634+4809
SDSS J163401.94+480940.2 is one of the bona-fide F sources,
and we can confirm this classification. In the VLBA image the
source shows only an unresolved core (Gu et al. 2015), and the
same is true for our map (Fig. C.35), in which only an unresolved
core of 900×340 pc can be seen. However, there might be an
elongated structure in the West direction, at P.A.∼270◦. The star
formation rate is 117 Myr−1, and q22 =0.15 (Caccianiga et al.
2015), suggesting that the radio might be dominated by the non-
thermal emission of the relativistic jet.
B.70. J1703+4540
SDSS J170330.38+454047.1 is a S source, which was classified
as a CSS with a turnover frequency below 150 MHz (Snellen
et al. 2004). Our in-band spectral indexes instead are flat, and as
already pointed out by Gu & Chen (2010) the previously mea-
sured steep indexes might be affected by variability. Indeed, our
broad-band index is also steep. The map of Fig. C.35 reveals
that the source is slightly extended toward South, at P.A. 170◦,
while the unresolved core has a deconvolved size of 265×120
pc. VLBA observations at 1.7 GHz revealed that the source has
a core-jet structure, with the one-sided relativistic jet directed to
South-West for 35 pc (Doi et al. 2011). The source has not been
detected at 37 GHz.
B.71. J1709+2348
SDSS J170907.80+234837.7 was classified bona-fide as a flat-
spectrum source, but our spectral indexes do not agree with this
hypothesis, suggesting instead a steep-spectrum. The map of
Fig. C.36 shows that the source is compact. The brightness tem-
perature is rather low, ∼545 K. In this source the star formation
rate is 23 Myr−1, with a q22 =0.96. This might indicate that
the radio emission of J1709+2348 might not be due only to the
non-thermal emission of a jet, but also to the star formation, in
agreement with the rather steep spectral indexes. Finally, spec-
tral index, morphology, and luminosity are consistent with those
of a low-luminosity CSS.
B.72. J1713+3523
FBQS J1713+3523 was classified as steep-spectrum below 1.4
GHz. This result is confirmed by all of our measurements. The
map shows a compact structure with a deconvolved core size
of 235×165 pc. The brightness temperature is approximately
1.7×104K, a value not different from those observed in many
of our radio-loud objects. It is worth noting that the source was
detected with VLBI at 22 GHz, and showed a flux of 138 mJy,
while it was not detected at 37 GHz. This huge flare at VLBI
scales seems to suggest that the core is highly non-thermal.
B.73. J2242+2943
Ark 564 is one of the most studied NLS1s, and in radio it
always showed, at all scales, an elongated emission directed
toward North, at P.A.∼0◦, associated with a mildly relativis-
tic outflow (e.g. Moran 2000; Gupta et al. 2013). Our map in
Fig. C.37 shows the same structure along with an unresolved
core of 330×110 pc. All the spectral indexes are rather steep,
and along wiht the fairly low brightness temperature (2750 K),
they suggest that star formation might contribute significantly to
the radio emission.
B.74. J2314+2243
RX J2314.9+2243 was classified as a steep-spectrum source,
but our in-band indexes seem to indicate a F classification. This
objects had a tentative γ-ray detection (Komossa et al. 2015),
which however was not confirmed by other studies (e.g. Liao
et al. 2015). The source in the map of Fig. C.37 do not show any
particular structure. The unresolved core with a size of 940×280
pc. The brightness temperature, ∼1.6×104K, is similar to that of
other radio-loud NLS1s. The source was not detected at 37 GHz.
Appendix C: Radio maps
23
M. Berton et al.: NLS1s with JVLA
Fig. C.1. Left panel: J0006+2012, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 0.24×0.22 kpc. Right panel:
J0100-0200, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 2.00×1.46 kpc.
Fig. C.2. Left panel: J0146-0040, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,1], beam size 0.84×0.59 kpc. Right panel:
J0347+0150, rms =19 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 0.32×0.24 kpc.
Fig. C.3. Left panel: J0629−0545, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 3.15×0.93 kpc. Right panel:
J0623+6340, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 0.21×0.11 kpc.
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Fig. C.4. Left panel: J0706+3901, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 1.76×0.93 kpc. Right panel:
J0713+3820, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 2.41×1.13 kpc.
Fig. C.5. Left panel: J0744+5149, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 4.78×2.21 kpc. Right panel:
J0752+2617, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,2], beam size 1.81×0.60 kpc.
Fig. C.6. Left panel: J0758+3920, rms =18 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 2.05×0.94 kpc. Right panel:
J0804+3853, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 1.55×1.42 kpc.
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Fig. C.7. Left panel: J0806+7248, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 1.32×0.72 kpc. Right panel:
J0814+5609, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 5.06×2.28 kpc.
Fig. C.8. Left panel: J0849+5108, rms =35 µJy, contour levels at -3, 3×2n, n ∈[0,11], beam size 2.84×2.71 kpc. Right panel:
J0850+4626, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 3.00×2.63 kpc.
Fig. C.9. Left panel: J0902+0443, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,11], beam size 8.52×2.59 kpc. Right panel:
J0913+3658, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 2.31×0.24 kpc.
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Fig. C.10. Left panel: J0925+5217, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 0.38×0.32 kpc. Right panel:
J0926+1244, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 0.55×0.80 kpc.
Fig. C.11. Left panel: J0937+3615, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 3.92×1.24 kpc. Right panel:
J0945+1915, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 3.09×1.80 kpc.
Fig. C.12. Left panel: J0948+5029, rms =15 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 0.57×0.49 kpc. Right panel:
J0952-0136, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 0.38×0.18 kpc.
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Fig. C.13. Left panel: J0957+2433, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,2], beam size 1.07×0.63 kpc. Right panel:
J1031+4234, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 2.59×2.23 kpc.
Fig. C.14. Left panel: J1034+3938, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 0.46×0.37 kpc. Right panel:
J1031+4234, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 4.32×2.73 kpc.
Fig. C.15. Left panel: J1038+4227, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 1.92×1.60 kpc. Right panel:
J1047+4725, rms =37 µJy, contour levels at -3, 3×2n, n ∈[0,11], beam size 3.00×2.33 kpc.
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Fig. C.16. Left panel: J1048+2222, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 3.14×2.00 kpc. Right panel:
J1102+2239, rms =15 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 3.76×2.37 kpc.
Fig. C.17. Left panel: J1110+3653, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 3.42×2.80 kpc. Right panel:
J1114+3241, rms =9µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 1.74×1.39 kpc.
Fig. C.18. Left panel: J1121+5351, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 0.97×0.85 kpc. Right panel:
J1138+3653, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 2.65×2.15 kpc.
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Fig. C.19. Left panel: J1146+3236, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 3.11×2.52 kpc. Right panel:
J1159+2838, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 1.78×1.44 kpc.
Fig. C.20. Left panel: J1203+4431, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 0.02×0.02 kpc. Right panel:
J1209+3217, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 0.83×0.76 kpc.
Fig. C.21. Left panel: J1215+5442, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 1.20×1.07 kpc. Right panel:
J1218+2948, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 0.14×0.11 kpc.
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Fig. C.22. Left panel: J1227+3214, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 1.23×1.01 kpc. Right panel:
J1238+3942, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,8], beam size 2.92×2.79 kpc.
Fig. C.23. Left panel: J1242+3317, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 0.43×0.33 kpc. Right panel:
J1246+0222, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 0.52×0.42 kpc.
Fig. C.24. Left panel: J1246+0238, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 2.80×2.09 kpc. Right panel:
J1302+1624, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 0.58×0.51 kpc.
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Fig. C.25. Left panel: J1305+5116, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 12.70×3.29 kpc. Right panel:
J1317+6010, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 2.74×1.19 kpc.
Fig. C.26. Left panel: J1333+4141, rms =14 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 8.31×4.52 kpc. Right panel:
J1337+2423, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 2.45×0.93 kpc.
Fig. C.27. Left panel: J1346+3121, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 4.10×1.66 kpc. Right panel:
J1348+2622, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 10.26×3.29 kpc.
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Fig. C.28. Left panel: J1355+5612, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,5], beam size 2.59×1.27 kpc. Right panel:
J1358+2658, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 6.24×1.95 kpc.
Fig. C.29. Left panel: J1402+2159, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,2], beam size 2.20×0.53 kpc. Right panel:
J1421+2824, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 8.31×2.67 kpc.
Fig. C.30. Left panel: J1443+4725, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,11], beam size 5.80×3.01 kpc. Right panel:
J1505+0326, rms =38 µJy, contour levels at -3, 3×2n, n ∈[0,12], beam size 2.28×1.79 kpc.
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Fig. C.31. Left panel: J1536+5433, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 0.53×0.33 kpc. Right panel:
J1537+4942, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 3.06×1.82 kpc.
Fig. C.32. Left panel: J1548+3511, rms =12 µJy, contour levels at -3, 3×2n, n ∈[0,10], beam size 9.30×2.56 kpc. Right panel:
J1555+1911, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,2], beam size 0.54×0.30 kpc.
Fig. C.33. Left panel: J1559+3501, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,4], beam size 0.91×0.25 kpc. Right panel:
J1612+4219, rms =39 µJy, contour levels at -3, 3×2n, n ∈[0,2], beam size 3.71×1.56 kpc.
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Fig. C.34. Left panel: J1629+4007, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,10], beam size 4.99×1.66 kpc. Right panel:
J1633+4718, rms =9µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 1.60×0.84 kpc.
Fig. C.35. Left panel: J1634+4809, rms =10 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 4.80×2.43 kpc. Right panel:
J1703+4540, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,9], beam size 0.89×0.48 kpc.
Fig. C.36. Left panel: J1709+2348, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,3], beam size 3.56×1.58 kpc. Right panel:
J1713+3523, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,6], beam size 1.16×0.58 kpc.
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Fig. C.37. Left panel: J2242+2943, rms =13 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 0.27×0.23 kpc. Right panel:
J2314+2243, rms =11 µJy, contour levels at -3, 3×2n, n ∈[0,7], beam size 1.96×1.27 kpc.
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