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We found several extranuclear (r >~ 3") X-ray nebulae within 40" (6.3 kpc at 32.5 Mpc) of the nucleus of the Seyfert galaxy NGC 2992. The net X-ray luminosity from the extranuclear sources is ~2-3 E39 erg/s (0.3-8.0 keV). The X-ray core itself (r <~ 1") is positioned at 9:45:41.95 -14:19:34.8 (J2000) and has a remarkably simple power-law spectrum w...
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Context 1
... addition to the very bright nucleus of NGC 2992, we detect twenty 3 X-ray point sources in the ACIS CCD that includes the NGC 2992/3 complex. We list X-ray properties of the twenty point sources in Table 1, and display the positions of the sources nearest to NGC 2992/3 in Figure 3. There are four sources within the R 25 ellipses of the two galaxies: source 7 (L X ≈ 10 39 erg s −1 ) is 17 ′′ (2.7 kpc) southeast of the nucleus of NGC 2992, and sources 9, 10, and 11 (L X ≈ 5 × 10 39 erg s −1 ) are all within ∼10 ′′ (1.6 kpc) of the center of NGC 2993. ...
Context 2
... the combined radial profiles from regions 2 and 8 for a PSF, we calculate an excess of 90±22 X-ray counts in this octant, from 20−40 ′′ (3.2−6.3 kpc). We found three other regions which had significant (>3σ) excess over our model PSF (see Figure 6d): a point-like source in region 4 (source 7 in Table 1) with 82±19 counts (from 15−25 ′′ ), diffuse emission with 75±22 counts in region 6, from 15−30 ′′ , and an extended source nearer to the nucleus (region 7, 10−20 ′′ ), with 74±24 counts. ...
Context 3
... was done by examining radial and horizontal cuts across the image and ensuring that the pixel values in source-free regions far away from the nucleus fluctuated No excess emission was found from our radial profile analyses of the hard (2.4−8.0 keV) X-ray emission. While not enough counts were typically available in narrow energy bands, we did notice that the point-like source in region 4 (point source 7 in Table 1) was significantly harder than expected for thermal plasma emission with kT of < ∼ 1 keV, with a significant number of photons with E > ∼ 1.5 keV. We list excess counts in several other energy bands in Table 2. Since the angular breaks that define our octants often pass through well-defined X- ray sources, we also list X-ray counts and 0.3−2.4 ...
Context 4
... excluded the very central region (with piled events) by rejecting all events within the "middle" ellipse in the lower left panel of Figure 4 (semi-major and semi-minor axes 3.4 ′′ × 2.7 ′′ ). We also excluded events from a faint point source (source 7, Table 1), and from a thin rectangular region enclosing the CCD readout streak. This extraction region thus includes a fraction of the X- ray core (section 3.1.2), ...
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Citations
... The figure-eight-shaped radio bubbles are likely expanding bubbles driven by AGN as suggested by García-Lorenzo 1 https://ned.ipac.caltech.edu et al. (2001) and Colbert et al. (2005). Recently, Xu & Wang (2022) suggested that the majority of the circumnuclear extended soft X-ray emission (r ∼ 750 pc) originates from AGN-driven outflows. ...
... In Figure 9, we compare the distribution of f Y with the [O iii] outflow component, extended soft X-ray emission reported by Xu & Wang (2022), and the nuclear radio bubble documented by Ulvestad & Wilson (1989). Colbert et al. (2005) and Xu & Wang (2022) found that there exists extended soft X-ray emission around the nucleus. Xu & Wang (2022) further revealed that the circumnuclear (r ∼ 750 pc) soft X-ray emission could be dominated by the hot gas associated with the AGN outflow traced by the nuclear figure-eight-shaped radio bubble. ...
In NGC 2992, a galaxy-scale ionized gas outflow driven by AGN has long been recognized, yet its impact on the host galaxy has remained elusive. In this paper, we utilize data from the archival Very Large Telescope (VLT)/MUSE to present a spatially resolved analysis of stellar populations in this galaxy. Two different stellar population templates are employed to fit the stellar continuum, allowing us to determine the light-weighted stellar age, metallicity, the fraction of the young stellar population (age $<100$ Myr, $P_{\rm Y}$), and the average age and metallicity of $P_{\rm Y}$. Our results reveal the presence of a very young stellar population ($\leq40$ Myr) within the dust lane and nearly along the galaxy's major axis. The light-weighted stellar age and the fraction of $P_{\rm Y}$ show negative trends along the major and minor axes. The average age and metallicity of $P_{\rm Y}$ present positive trends with increasing distance, except along the northern direction of the major axis. Within the circumnuclear region ($<1$ kpc), the distribution of the young stellar population is spatially anti-correlated with the AGN outflow cone. The highest fraction of $P_{\rm Y}$ is observed at the outskirts of the nuclear radio bubble in the northern region near the nucleus. Considering the coupling efficiency and timescales, we propose that the AGN outflow in this galaxy may exert both negative and positive feedback on its host. Additionally, the star formation and the AGN activities could be attributed to the interaction between NGC 2992 and NGC 2993.
... Spatially extended soft X-ray and a significant soft excess in its spectrum have been observed for NGC 2992 previously by ROSAT (Colbert et al. 1998). Colbert et al. (2005) have studied this source in detail and found several extranuclear X-ray sources with distances of r 3″ from the nucleus by Chandra. However, the fluxes of these sources cannot account for most of the soft excess. ...
... García-Lorenzo et al. (2001) further suggested that the figure-eight-shaped radio structure could well be expanding bubbles according to the spatial correlation between an extended arc-shaped emission detected in [O III] and the radio bubbles. Because the X-ray peak is coincident with the core of the bubbles, Colbert et al. (2005) suggested that the radio feature could be inflated by the AGN instead of a starburst. More recently, Irwin et al. (2017) reported on C-band (5-7 GHz) observations of NGC 2992, including the clear detection of a nuclear bipolar radio outflow revealed in linearly polarized emission, strongly supporting presence of an AGN-related outflow. ...
... The spectral fitting was performed with the XSPEC package (version 12.9.1 m Arnaud 1996). Colbert et al. (2005) have previously noted extended asymmetric soft X-ray emission from ∼2.5″ to 4″ in 0.3-1.0 keV band using the Chandra ACIS data without a grating. ...
The innermost region of the Seyfert galaxy NGC 2992 has long been suspected to be the location of intense AGN–host galaxy interaction, but photon pile up in previous high-resolution observations hampered the study of the soft X-ray excess and the interaction near its nucleus. We present an X-ray imaging and spectroscopic analysis of the circumnuclear (1″–3″) region of NGC 2992 using the zeroth-order image of a 135 ks grating observation obtained with Chandra, which captured the nucleus in a historically low flux state. Extended soft X-ray emission is detected in the circumnuclear region with an observed luminosity of L X ∼ 7 × 10 ³⁹ erg s ⁻¹ . The majority of the previous, puzzling detection of soft excess could be associated with the outflow, indicated by the morphological correspondences between the soft X-ray emission and figure-eight-shaped radio bubbles. An anomalous narrow emission line with a centroid energy of ∼4.97 keV is found. If attributed to redshifted highly ionized iron emission (e.g., Fe xxv ), the required outflow velocity is ∼0.23 c . An alternative explanation is that this line emission could be produced by the nuclear spallation of iron. We also find extended, asymmetric Fe K α emission along the galactic disk, which could originate from reflection by cold gas on ∼200 pc scale.
... Spatially extended soft X-ray and significant soft excess in the spectrum have been observed in NGC 2992 previously by ROSAT (Colbert et al. 1998). Colbert et al. (2005) have studied this source in detail and found several extranuclear X-ray sources with distances r 3 from the nucleus by Chandra. However, the flux of these sources cannot account for most of the soft excess. ...
... García-Lorenzo et al. (2001) further suggested that the figure-eight-shaped radio structure could well be expanding bubbles according to the spatial correlation between an extended arcshaped emission detected in [O iii] and the radio bubbles. Because the X-ray peak is coincident with the core of the bubbles, Colbert et al. (2005) suggested that the radio feature could be inflated by an AGN instead of a starburst. More recently, Irwin et al. (2017) reported on C-band (5-7 GHz) observation of NGC 2992 and a clear detection of nuclear bipolar radio outflow revealed in linearly polarized emission, strongly support presence of the AGN-related outflow. ...
... 3.1. Spatial analysis Colbert et al. (2005) have previously noted extended asymmetric soft X-ray emission from ∼2.5 to 4 in 0.3-1.0 keV band using the Chandra ACIS data without grating. ...
The inner-most region of the Seyfert galaxy NGC 2992 has long been suspected to be the location of intense AGN-host galaxy interaction, but photon pile-up in previous high-resolution observations hampered the study of soft X-ray excess and the interaction near its nucleus. We present an X-ray imaging spectroscopic analysis of the circumnuclear ($1^{\prime\prime}$--$3^{\prime\prime}$) region of NGC 2992 using the zeroth-order image of a 135 ks grating observation obtained with Chandra, which captured the nucleus in a historically low flux state. Extended soft X-ray emission is detected in the circumnuclear region with observed luminosity $L_{\rm X} \sim 7 \times 10^{39}\rm\ erg\ s^{-1}$. The majority of previously puzzling detection of soft excess could be associated with the outflow, indicated by the morphological correspondences between soft X-ray emission and figure-eight-shaped radio bubbles. An anomalous narrow emission line with the centroid energy $\sim4.97$ keV is found. If attributed to redshifted highly ionized iron emission (e.g., Fe xxv), the required outflow velocity is $\sim0.23\,c$. An alternative explanation is that this line emission could be produced by the nuclear spallation of iron. We also find asymmetric extended Fe K$\alpha$ emission along the galactic disk, which could originate from reflection by cold gas on $\sim 200$ pc scale.
... : 23.5], with step of 0.1. Then, the apec model was used to reproduce thermal emission from extra-nuclear material observed with Chandra (Colbert et al. 2005). We fitted the temperature and the normalisation for the apec component and the column density, the ionisation and the normalisation of the Cloudy one. ...
We report on the short and long term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM-Newton and NuSTAR. Swift targeted the source more than 100 times between 2019 and 2021 in the context of two monitoring campaigns. Both time-averaged and time-resolved analyses are performed, and we find that the short-to-long term spectral properties of NGC 2992 are dominated by a highly variable nuclear continuum. The source varied in the 2-10 keV energy band from 0.6 to 12 $\times$ 10$^{-11}$ erg cm$^{-2}$ s$^{-1}$ during the two year long Swift monitoring. The fastest 2-10 keV flux change (by a factor of $\sim60\%$) occurred on a timescale of a few hours. The overall emission spectrum of the source is consistent with a power law-like continuum ($\Gamma=1.69\pm0.01$) absorbed by a constant line-of-sight column density N$_{H}=(7.8\pm0.1)\times$ 10$^{21}$ $\rm cm^{-2}$. The reflected emission is likely due to matter with an average column density N$_{\rm H}=(9.6\pm2.7)\times$ 10$^{22}$ $\rm cm^{-2}$, thus NGC 2992 appears to have a globally Compton-thin circumnuclear medium. This scenario is fully supported by an independent analysis of the fractional variability and by XMM-Newton multi-year spectra.
... The whole model has been then multiplied by a Galactic absorption of 4.8 × 10 20 cm −2 (Kalberla et al. 2005). We also included an APEC model to reproduce the thermal emission from extra-nuclear material previously observed with Chandra at low energies (Colbert et al. 2005). At this stage of the spectral analysis, the photon index is initially fixed to Horizontal solid and dashed red lines indicate best-fitting value and error bars when the Fe K α flux is tied between the nine spectra. ...
The Seyfert 2 galaxy NGC 2992 has been monitored eight times by XMM-Newton in 2010 and then observed again in 2013, while in 2015 it was simultaneously targeted by Swift and NuSTAR. XMM-Newton always caught the source in a faint state (2-10 keV fluxes ranging from 0.3 to 1.6 × 10⁻¹¹ erg cm⁻² s⁻¹), but NuSTAR showed an increase in the 2-10 keV flux up to 6 × 10-11 erg cm⁻² s⁻¹.We find possible evidence of an Ultra Fast Outflow with velocity v1 = 0.21 ± 0.01c (detected at about 99 per cent confidence level) in such a flux state. The UFO in NGC 2992 is consistent with being ejected at a few tens of gravitational radii only at accretion rates greater than 2 per cent of the Eddington luminosity. The analysis of the low-flux 2010/2013 XMM data allowed us to determine that the Iron K α emission line complex in this object is likely the sum of three distinct components: a constant, narrow one due to reflection from cold, distant material (likely the molecular torus); a narrow, but variable one which is more intense in brighter observations and a broad relativistic one emitted in the innermost regions of the accretion disc, which has been detected only in the 2003 XMM observation. © 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
... Furthermore, extended emission was neither detected by the ROSAT HRI nor evident in the ASCA spectrum. Evidence of extended, soft X-ray emission toward the southeast (coincident with the southeast radio bubble) between 0.3 and 0.6 kpc from the core was found in a Chandra-Advanced CCD Imaging Spectrometer (ACIS) observation, but Colbert et al. (2005) report that the bulk (75%-80%) of the soft excess emission is undetected or unresolved by ACIS. Since it did not show up in the "core" spectrum (extracted from the readout streak), they suggest that the source of this emission lies between ∼150 and 500 pc from the nucleus. ...
... Since it did not show up in the "core" spectrum (extracted from the readout streak), they suggest that the source of this emission lies between ∼150 and 500 pc from the nucleus. Colbert et al. (2005) note that the extended soft excess could be due to AGN photoionization and/or a starburst-driven superwind-the results were ambiguous. Their derived thermal X-ray temperature is consistent with velocities for extended NLR gas in a cone on the southeastern side of the nucleus found by Allen et al. (1999) and Veilleux et al. (2001). ...
... There are two diffuse figure-eight-shaped radio bubbles in NGC2992; since the X-ray core is at their intersection, the bubbles could be due to the AGN (as opposed to a starburst; see Colbert et al. 2005). Veilleux et al. (2001) detected a biconical outflow that extends to ∼2.8 kpc along the minor axis of the galactic disk (to the southeast and northwest of the nucleus; aligned with the large-scale radio structure, but misaligned by ∼44°from the arcsecond-scale figure-eight radio structure) with the TAURUS-2 imaging Fabry-Perot interferometer on the 3.9 m Anglo-Australian Telescope. ...
We present the narrow emission-line structure revealed by a 135 ks Chandra observation of Seyfert galaxy NGC 2992, using the High Energy Transmission Grating Spectrometer. The source was observed in an historically low-flux state. Using a Bayesian Block search technique, we detected neutral Si Kα and S Kα fluorescence and two additional lines that are consistent with redshifted, ionized Si emission. The latter two features are indicative of a photoionized outflow with a velocity of < ∼ km s-1. We also observed prominent, unresolved line emission at the rest energy of Fe Kα, with a 90% confidence FWHM velocity width of < 2000 km s-1 (<2800 km s-1) and equivalent width of 406-1148 eV (288-858 eV) when broad Fe Kα line emission, as detected by Suzaku, was (was not) included in the model. © 2017. The American Astronomical Society. All rights reserved.
... 11 http://space.mit.edu/ASC/MARX/ 12 Details including verification of this procedure are available at http://www.astro.isas.jaxa.jp/∼tsujimot/arfcorr.html. analyses of Chandra/ACIS observations of NGC 6251 (Evans et al. 2005) and NGC 2992 (Colbert et al. 2005). The X-ray spectra were extracted using photons flagged as source events by acisreadcorr. ...
We present new X-ray spectral data for the Seyfert 1 nucleus in NGC 4151 observed with Chandra for ~200 ks. A significant ACIS pileup is present, resulting in a nonlinear count rate variation during the observation. With pileup corrected spectral fitting, we are able to recover the spectral parameters and find consistency with those derived from unpiled events in the ACIS readout streak and outer region from the bright nucleus. The absorption corrected 2-10 keV flux of the nucleus varied between 6 × 10–11 erg s–1 cm–2 and 10–10 erg s–1 cm–2 (L 2-10 keV ~ 1.3-2.1 × 1042 erg s–1). Similar to earlier Chandra studies of NGC 4151 at a historical low state, the photon indices derived from the same absorbed power-law model are Γ ~ 0.7-0.9. However, we show that Γ is highly dependent on the adopted spectral models. Fitting the power-law continuum with a Compton reflection component gives Γ ~ 1.1. By including passage of non-uniform X-ray obscuring clouds, we can reproduce the apparent flat spectral states with Γ ~ 1.7, typical for Seyfert 1 active galactic nuclei. The same model also fits the hard spectra from previous ASCA "long look" observation of NGC 4151 in the lowest flux state. The spectral variability during our observation can be interpreted as variations in intrinsic soft continuum flux relative to a Compton reflection component that is from distant cold material and constant on short timescale, or variations of partially covering absorber in the line of sight toward the nucleus. An ionized absorber model with ionization parameter log ξ ~ 0.8-1.1 can also fit the low-resolution ACIS spectra. If the partial covering model is correct, adopting a black hole mass M ☉ we constrain the distance of the obscuring cloud from the central black hole to be r 9 lt-day, consistent with the size of the broad emission line region of NGC 4151 from optical reverberation mapping.
... This value is similar to Gilli et al.'s measurement with BeppoSAX of N H = 9.0 ± 0.3 × 10 21 cm −2 , from when the galaxy was in a high X-ray and optical state. Throughout the history of NGC 2992's observations, the X-ray flux has been seen to vary dramatically, from f 2−10keV = 0.63 × 10 −11 ergs cm −2 s −1 observed by Gilli et al. with BeppoSAX in 1997 (Gilli et al. 2000– 6 – to f 2−10keV = 8.88 × 10 −11 ergs cm −2 s −1 observed by Murphy et al. with RXTE in 2005 (Murphy et al. 2007), but the X-ray column has remained virtually constant at ∼ 10 22 cm −2 (Gilli et al. 2000; Colbert et al. 2005; Yaqoob et al. 2007). The observed X-ray columns are two to three times higher than those estimated by the reddening values. ...
New spectra of NGC 2992 from the Cerro Tololo Inter-American Observatory show that this nearby AGN has changed its type classification to a Seyfert 2 in 2006. It was originally classified as a Seyfert 1.9, and has been previously seen as a Seyfert 1.5 with strong broad Halpha emission. A comparison of the reddening and equivalent hydrogen column density derived for the narrow-line region from these new data with those previously calculated for different regions closer to the nucleus shows them to be very similar, and suggests that these different regions are all being absorbed by the same opacity source, a large 100-pc scale dust lane running across the nucleus. However, obscuration by dust in this lane is probably not responsible for classification changes which occur in only a few years. It is more likely that NGC 2992's observed variations are due to a highly variable ionizing continuum. We therefore conclude that, although NGC 2992 was originally identified as a Seyfert 1.9, this was not because of an oblique viewing angle through the atmosphere of a central dusty torus, but because its active nucleus was identified when it was in a low continuum state. Comment: To be published in the Astronomical Journal. 19 pages, with 5 figures
We present an analysis of the gas kinematics in NGC 2992 based on VLT/MUSE, ALMA, and VLA data. Our aim is to characterise the disc, the wind, and their interplay in the cold molecular and warm ionised phases. NGC 2992 is a changing-look Seyfert known to host both a nuclear ultrafast outflow (UFO), and an AGN-driven kiloparsec-scale ionised wind. CO(2−1) and H α arise from a multiphase disc with an inclination of 80 deg and radii of 1.5 and 1.8 kpc, respectively. By modelling the gas kinematics, we find that the velocity dispersion of the cold molecular phase, σ gas , is consistent with that of star forming galaxies at the same redshift, except in the inner 600 pc region, and in the region between the cone walls and the disc, where σ gas is a factor of 3−4 larger than in star forming galaxies for both the cold molecular and the warm ionised phases. This suggests that a disc–wind interaction locally boosts the gas turbulence. We detect a clumpy ionised wind in H β , [O III], H α , and [N II] distributed in two wide-opening-angle ionisation cones reaching scales of 7 kpc (40 arcsec). The [O III] wind expands with a velocity exceeding −1000 km s ⁻¹ in the inner 600 pc, which is a factor of approximately five greater than the previously reported wind velocity. Based on spatially resolved electron density and ionisation parameter maps, we infer an ionised outflow mass of M of, ion = (3.2 ± 0.3)×10 ⁷ M ⊙ , and a total ionised outflow rate of Ṁ of,ion = 13.5 ± 1 M ⊙ yr ⁻¹ . We detected ten clumps of cold molecular gas located above and below the disc in the ionisation cones, reaching maximum projected distances of 1.7 kpc and showing projected bulk velocities of up to 200 km s ⁻¹ . On these scales, the wind is multiphase, with a fast ionised component and a slower molecular one, and a total mass of M of, ion + mol = 5.8 × 10 ⁷ M ⊙ , of which the molecular component carries the bulk of the mass, namely M of, mol = 4.3 × 10 ⁷ M ⊙ . The dusty molecular outflowing clumps and the turbulent ionised gas are located at the edges of the radio bubbles, suggesting that the bubbles interact with the surrounding medium through shocks, as also supported by the [O I]/H α ratio. Conversely, both the large opening angle and the dynamical timescale of the ionised wind detected in the ionisation cones on 7 kpc scales indicate that this is not related to the radio bubbles but instead likely associated with a previous AGN episode. Finally, we detect a dust reservoir that is co-spatial with the molecular disc, with a cold dust mass of M dust = (4.04 ± 0.03)×10 ⁶ M ⊙ , which is likely responsible for the extended Fe K α emission seen on 200 pc scales in hard X-rays and interpreted as reflection by cold dust.
We report on the short and long term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM-Newton and NuSTAR. Swift targeted the source more than 100 times between 2019 and 2021 in the context of two monitoring campaigns. Both time-averaged and time-resolved analyses are performed, and we find that the short-to-long term spectral properties of NGC 2992 are dominated by a highly variable nuclear continuum. The source varied in the 2-10 keV energy band from 0.6 to 12 × 10−11 erg cm−2 s−1 during the two year long Swift monitoring. The fastest 2-10 keV flux change (by a factor of $\sim 60{{\ \rm per\ cent}}$) occurred on a timescale of a few hours. The overall emission spectrum of the source is consistent with a power law-like continuum (Γ = 1.69 ± 0.01) absorbed by a constant line-of-sight column density NH = (7.8 ± 0.1) × 1021$\rm cm^{-2}$. The reflected emission is likely due to matter with an average column density NH = (9.6 ± 2.7) × 1022$\rm cm^{-2}$, thus NGC 2992 appears to have a globally Compton-thin circumnuclear medium. This scenario is fully supported by an independent analysis of the fractional variability and by XMM-Newton multi-year spectra.
