Sahar Allam

Using the full 6 years of imaging data from the Dark Energy Survey, we study the surface brightness profiles of galaxy cluster central galaxies and intra-cluster light. We apply a ‘stacking’ method to over 4000 galaxy clusters identified by the redMaPPer cluster finder in the redshift range of 0.2−0.5. This yields high-signal-to-noise circularly av...

Background Ehrlich ascites carcinoma (EAC) is a rapidly growing and undifferentiated tumor that can prompt oxidative stress and liver toxicity, whereas chitosan and Grifola Frondosa have widely recognized biological qualities. Therefore, our study designed to assess the potential ameliorative ability of chitosan nanoparticles (CS NPs) and Grifola F...

In this study, the impact of chitosan (CS) and maitake (GF) nanoparticles towards the renal toxicity induced by Ehrlich ascites carcinoma (EAC) in vivo model was conducted. Besides benchmark negative control group, EAC model was constructed by intraperitoneal injection (i.p.) of 2.5 × 10 ⁶ cells. Alongside positive control, two groups of EAC‐bearin...

Using the full six years of imaging data from the Dark Energy Survey, we study the surface brightness profiles of galaxy cluster central galaxies and intra-cluster light. We apply a ``stacking'' method to over four thousand galaxy clusters identified by the redMaPPer cluster finding algorithm in the redshift range of 0.2 to 0.5. This yields high si...

Cosmological analyses with type Ia supernovae (SNe Ia) often assume a single empirical relation between color and luminosity ($\beta$) and do not account for varying host-galaxy dust properties. However, from studies of dust in large samples of galaxies, it is known that dust attenuation can vary significantly. Here we take advantage of state-of-th...

We measure the projected number density profiles of galaxies and the splashback feature in clusters selected by the Sunyaev–Zel’dovich effect from the Advanced Atacama Cosmology Telescope (AdvACT) survey using galaxies observed by the Dark Energy Survey (DES). The splashback radius is consistent with CDM-only simulations and is located at 2.4 − 0.4...

On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An extensive search for an optical counterpart of this event, designated GW190814, was undertaken using DECam on the CTIO Blanco 4-m telescope. Target of opportunity interrupts were issued on 8...

We present optical follow-up imaging obtained with the Katzman Automatic Imaging Telescope, Las Cumbres Observatory Global Telescope Network, Nickel Telescope, Swope Telescope, and Thacher Telescope of the LIGO/Virgo gravitational wave (GW) signal from the neutron star-black hole (NSBH) merger GW190814. We searched the GW190814 localization region...

We extend the SDSS Stripe 82 Standard Stars catalogue with post-2007 SDSS imaging data. This improved version lists averaged SDSS ugriz photometry for nearly a million stars brighter than r ∼ 22 mag. With 2-3× more measurements per star, random errors are 1.4-1.7× smaller than in the original catalogue, and about 3× smaller than for individual SDSS...

We extend the SDSS Stripe 82 Standard Stars Catalog with post-2007 SDSS imaging data. This improved version lists averaged SDSS ugriz photometry for nearly a million stars brighter than r~22 mag. With 2-3x more measurements per star, random errors are 1.4-1.7x smaller than in the original catalog, and about 3x smaller than for individual SDSS runs....

We present the statistical methods that have been developed to analyse the OzDES reverberation mapping sample. To perform this statistical analysis we have created a suite of customisable simulations that mimic the characteristics of each individual source in the OzDES sample.These characteristics include: the variability in the photometric and spe...

We study a class of decaying dark matter models as a possible resolution to the observed discrepancies between early- and late-time probes of the universe. This class of models, dubbed DDM, characterizes the evolution of comoving dark matter density with two extra parameters. We investigate how DDM affects key cosmological observables such as the C...

Binary supermassive black holes (BSBHs) are expected to be a generic byproduct from hierarchical galaxy formation. The final coalescence of BSBHs is thought to be the loudest gravitational wave (GW) siren, yet no confirmed BSBH is known in the GW-dominated regime. While periodic quasars have been proposed as BSBH candidates, the physical origin of...

Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confirmed quasars with a median redshift of 1.8 in a 4.6 deg2 overlapping region of the Dark Energy Survey Supernova (DES-SN) fields and the Sloan Digital Sky Survey Stripe 82...

Binary supermassive black holes are expected to be a generic byproduct from hierarchical galaxy formation. The final coalescence of BSBHs is thought to be the loudest gravitational wave siren in the universe, yet no confirmed BSBH is known in the GW-dominated regime. While periodic quasars have been proposed as BSBH candidates, the physical origin...

Periodically variable quasars have been suggested as close binary supermassive black holes. We present a systematic search for periodic light curves in 625 spectroscopically confirmed quasars with a median redshift of 1.8 in a 4.6 deg$^2$ overlapping region of the Dark Energy Survey Supernova (DES-SN) fields and the Sloan Digital Sky Survey Stripe...

We measure the projected number density profiles of galaxies and the splashback feature in clusters selected by the Sunyaev--Zeldovich (SZ) effect from the Advanced Atacama Cosmology Telescope (AdvACT) survey using galaxies observed by the Dark Energy Survey (DES). The splashback radius for the complete galaxy sample is consistent with theoretical...

We report the identification of a low-mass active galactic nucleus (AGN), DES J0218−0430, in a redshift z = 0.823 galaxy in the Dark Energy Survey (DES) Supernova field. We select DES J0218−0430 as an AGN candidate by characterizing its long-term optical variability alone based on DES optical broad-band light curves spanning over 6 yr. An archival...

We report on small-amplitude optical variability and recent dissipation of the unusually persistent broad emission lines in the blue compact dwarf galaxy PHL 293B. The galaxy’s unusual spectral features (P Cygni-like profiles with ∼800 km s ⁻¹ blueshifted absorption lines) have resulted in conflicting interpretations of the nature of this source in...

We perform a joint analysis of the counts and weak lensing signal of redMaPPer clusters selected from the Dark Energy Survey (DES) Year 1 dataset. Our analysis uses the same shear and source photometric redshifts estimates as were used in the DES combined probes analysis. Our analysis results in surprisingly low values for $S_8 =\sigma_8(\Omega_{\r...

Background and Objective: Chitosan, the deacetylated derivative of chitin, is a natural D-glucosamine polymer that can be extracted from the shells of seafood such as lobsters and prawns crabs which have obtained a great interest in cancer therapy. This study aimed to investigate the hepatic and renal protective potential of chitosan nanoparticles...

We present the first detailed elemental abundances in the ultra-faint Magellanic satellite galaxies Carina II (Car II) and Carina III (Car III). With high-resolution Magellan/MIKE spectroscopy, we determined abundances of nine stars in Car II including the first abundances of an RR Lyrae star in an ultra-faint dwarf galaxy; and two stars in Car III...

In the current model of early Solar System evolution, the stable members of the Jovian and Neptunian Trojan populations were captured into resonance from the leftover reservoir of planetesimals during the outward migration of the giant planets. As a result, both Jovian and Neptunian Trojans share a common origin with the primordial disk population,...

We present ~1" resolution (~2 kpc in the source plane) observations of the CO(1-0), CO(3-2), Halpha, and [N II] lines in the strongly-lensed z=2.26 star-forming galaxy SDSS J0901+1814. We use these observations to constrain the lensing potential of a foreground group of galaxies, and our source-plane reconstructions indicate that SDSS J0901+1814 is...

For 3p63d4l where l=s,p,d,f states in Ni+8, we evaluated both oscillator strengths and energy levels to investigate the probability of laser wavelengths production in the soft X-ray and XUV regions. The calculations are executed using CIV3 and LANL codes. By comparing the values of our results with other published experimental and theoretical data,...

Using stellar population models, we predicted that the Dark Energy Survey (DES) – due to its special combination of area (5000 deg²) and depth (i = 24.3) – would be in the position to detect massive (≳10¹¹ M⊙) galaxies at |$z$| ∼ 4. We confront those theoretical calculations with the first ∼150 deg² of DES data reaching nominal depth. From a catalo...

We present a suite of 18 synthetic sky catalogs designed to support science analysis of galaxies in the Dark Energy Survey Year 1 (DES Y1) data. For each catalog, we use a computationally efficient empirical approach, ADDGALS, to embed galaxies within light-cone outputs of three dark matter simulations that resolve halos with masses above ~5x10^12...

Objects: Amitriptyline is a widely used tricyclic antidepressant. Amitriptyline is well-known for its cardiovascular side effects and toxicity in psychiatric patients. However, the mechanisms underlying the cardiovascular side effects of amitriptyline remain largely undefined. Aims: This study aims to show the hematological and biochemical changes...

In the current model of early Solar System evolution, the stable members of the Jovian and Neptunian Trojan populations were captured into resonance from the leftover reservoir of planetesimals during the outward migration of the giant planets. As a result, both Jovian and Neptunian Trojans share a common origin with the primordial disk population,...

Using stellar population models, we predicted that the Dark Energy Survey (DES) - due to its special combination of area (5000 deg. sq.) and depth ($i = 24.3$) - would be in the position to detect massive ($\gtrsim 10^{11}$ M$_{\odot}$) galaxies at $z \sim 4$. We confront those theoretical calculations with the first $\sim 150$ deg. sq. of DES data...

Transneptunian objects (TNOs) are a source of invaluable information to access the history and evolution of the outer solar system. However, observing these faint objects is a difficult task. As a consequence, important properties such as size and albedo are known for only a small fraction of them. Now, with the results from deep sky surveys and th...

In the current model of early Solar System evolution, the stable members of the Jovian and Neptunian Trojan populations were captured into resonance from the protoplanetesimal disk during the outward migration of the giant planets. As a result, both Jovian and Neptunian Trojans share a common origin with the primordial disk population, whose other...

We report upon the follow up of 34 candidate lensed quasars found in the Dark Energy Survey using NTT-EFOSC, Magellan-IMACS, KECK-ESI and SOAR-SAMI. These candidates were selected by a combination of double component fitting, morphological assessment and color analysis. Most systems followed up are indeed composed of at least one quasar image and 1...

We report the discovery and dynamical analysis of 2015 BP$_{519}$, an extreme Trans-Neptunian Object detected detected by the Dark Energy Survey at a heliocentric distance of 55 AU and absolute magnitude Hr= 4.3. The current orbit, determined from a 1110-day observational arc, has semi-major axis $a\approx$ 450 AU, eccentricity $e\approx$ 0.92 and...

We present a novel approach for creating science-ready catalogs through a software infrastructure developed for the Dark Energy Survey (DES). We integrate the data products released by the DES Data Management and additional products created by the DES collaboration in an environment known as DES Science Portal. Each step involved in the creation of...

We use mock galaxy survey simulations designed to resemble the Dark Energy Survey Year 1 (DES Y1) data to validate and inform cosmological parameter estimation. When similar analysis tools are applied to both simulations and real survey data, they provide powerful validation tests of the DES Y1 cosmological analyses presented in companion papers. W...

On 17 August 2017, the Advanced LIGO1 and Virgo2 detectors observed the gravitational-wave event GW170817—a strong signal from the merger of a binary neutron-star system3. Less than two seconds after the merger, a γ-ray burst (GRB 170817A) was detected within a region of the sky consistent with the LIGO–Virgo-derived location of the gravitational-w...

The detection of GW170817 (ref. 1) heralds the age of gravitational-wave multi-messenger astronomy, with the observations of gravitational-wave and electromagnetic emission from the same transient source. On 17 August 2017 the network of Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo detectors observed GW170817, a str...

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of with respect to the merger t...

We report the discovery of a new star cluster, DES 3, in the constellation of Indus, and deeper observations of the previously identified satellite DES J0222.7$-$5217 (Eridanus III). DES 3 was detected as a stellar overdensity in first-year Dark Energy Survey data, and confirmed with deeper photometry from the 4.1 metre Southern Astrophysical Resea...

We present a novel approach for creating science-ready catalogs through a software infrastructure developed for the Dark Energy Survey (DES). We integrate the data products released by the DES Data Management and additional products created by the DES collaboration in an environment known as DES Science Portal. Each step involved in the creation of...

We present the Dark Energy Survey (DES) Science Portal, an integrated web-based data interface designed to facilitate scientific analysis. We demonstrate how the Portal can provide a reliable environment to access complete data sets, provide validation algorithms and metrics in the case of multiple methods and training configurations, and maintain...

The energy levels, oscillator strengths, and E1 transition probabilities have been calculated for calcium-like ions with Z = 22 − 30 (excluding iron). The calculations have been executed using the CIV3 and LANL codes for a set of configuration arrays including 63 fine structure levels (in this paper we mentioned for examples about 40 energy levels)...

Excitation energies and transition probabilities for the 1s22s22p63s23p63d10, and the 1s22s22p63s23p63d94l (l= s, p,d, and f) configurations in nickel-like tin have been used to calculate the reduced population of 99 fine structure levels over a wide range of electron densities and at different electron plasma temperatures. The gain coefficients fo...

The present work aimed to study the variation in the plasma parameters (temperature and density) of the Ti plasma generated by 1,064 and 532 nm lasers at different ambient N2 pressures for different delay times. The characterization of the plasma-assisted pulsed laser ablation of the titanium target is discussed. The emission spectra of the titaniu...

The enhancement of the emission intensity of spectra using a single laser for induced breakdown spectroscopy (LIBS) in atmospheric air is investigated based on methodology previously published in Applied Physics B: Lasers and Optics accepted 12 July 2013 DOI 10.1007/s00340-013-5589-9 [1]. The laser energy per pulse in the present study is 188 mJ an...

Energy levels, oscillator strengths, and transition probabilities for transitions among the 14 LS states belonging to configurations of sulfur-like iron, Fe XI, have been calculated. These states are represented by configuration interaction wavefunctions and have configurations 3s23p4, 3s3p5, 3s23p33d, 3s23p34s, 3s23p34p, and 3s23p34d, which give r...

Evaluation of plasmas produced and optimized for improving the capability of convenential laser induced breakdown spectroscopy (LIBS) for analytical purposes of solid samples is the main goal of the present work. The plasma produced in the present study was generated by focusing a single nano-second Nd:YAG laser at the fundamental wavelength of 106...

The energy levels, oscillator strengths, line strengths, and transition probabilities for transitions among the terms belonging to the 3s23p2, 3s3p3, 3s23p3d, 3s23p4s, 3s23p4p and 3s23p4d configurations of silicon-like ions (Zn XVII, Ga XVIII, Ge XIX, and As XX) have been calculated using the configuration-interaction code CIV3. The calculations ha...

LIBS of nanosecond pulsed Nd: YAG laser (1064 nm) produced plasma from a set of nanomaterial and bulk targets (ZnO, Fe 3 O 4 , Ag 2 O, TiO 2 , SiO 2 and Al 2 O 3) is investigated at laser fluencies in the range 86 J/cm 2 to 2.5 J/cm 2. The optical emission spectra is recorded at the gate and time delay of 1 μs after the onset of the plasma in air h...

The transitions between 4p and 4d levels have been studied to examine the possibility of laser wavelengths production in the soft X-ray region. The oscillator strengths of the transitions 3p4p (3S,3P,3D)→3p4d (3Po,3Do,3Fo) have been calculated using CIV3 code. Using calculated oscillator strengths, the excitation rate coefficients, reduced populati...

Laser-induced breakdown spectroscopy (LIBS) has proven to be extremely versatile, providing multielement analysis in real time without sample preparation. The principle is based on the ablation of a small amount of target material by interaction of a strong laser beam with a solid target. The laser must have sufficient energy to excite atoms and to...

Time-resolved optical emission spectroscopy has been successfully employed to investigate the evolution of plasma produced by the interaction of IR- and visible-pulsed laser beams with a titanium target in ambient air at atmospheric pressure. The characterization of the plasma-assisted pulsed laser ablation of the titanium target is discussed in th...

In this article we will present an attempt to measure the Stark broadening parameter of the Zn I-line at 636.23 nm utilizing the optical emission spectroscopy (OES) technique, taking into consideration the possibility of existence of self absorption. This method is standing on comparison of the Lorentzian FWHM and spectral line intensity of the unk...

Utilizing the laser induced breakdown spectroscopy (LIBS), we report, a strong enhanced emission from laser produced plasma in air from Zinc nanomaterial in comparison with the corresponding bulk samples. The enhancement favored certain Nd:YAG laser harmonics wavelengths. Quite interestingly, laser radiation harmonics realize a two orders of magnit...

The aim of the present work is to evaluate the effect of the laser beam energy on the properties of the plasma generated by focusing an intense laser beam on an Al solid target in air at atmospheric pressure. Plasma is generated using a Brilliant Nd–YAG pulsed laser from Quantel at the fundamental wavelength; its pulse energy is 750 mJ and the puls...

Fine-structure calculations of energy levels, oscillator strengths, and transition probabilities for transitions among the terms belonging to 3s23p2, 3s3p3, 3s23p3d, 3s23p4s, 3s23p4p, 3s23p4d, 3s23p5s and 3s23p5p configurations of silicon-like ions P II, S III, Cl IV, Ar V and K VI have been calculated using configuration-interaction version 3 (CIV...

In this article, we will report an experimental evidence of enhanced LIBS emission upon replacing a Bulk-Based ZnO target by the corresponding Nano-Based target. The plasma was initiated via interaction of a Nd:YAG laser at the fundamental wavelength with both targets in open air under the same experimental conditions. The measurements show an enha...

A time-resolved diagnostic technique was used to investigate the emission spectra from the copper plasma produced by the high power Q-switched Nd : YAG laser that generates 670 mJ pulses in 6 ns of duration at a frequency 10 Hz and 1064 nm pulse-laser ablation in air. Spectroscopic measurements were devoted to determine the plasma temperature by us...

The diode laser atomic absorption spectroscopy (DLAAS) technique has been utilized to assess the degree of optical opacity of plasma at the wavelength of the Hα-line. The plasma is produced at atmospheric conditions by focusing a 6 ns Nd:YAG laser pulse at 1.064 μm on different solid target materials including aluminum, iron and titanium as major e...

Within the effective mass approximation, we investigated theoretically the ground-state energy of a single particle and the binding energy of the neutral donor impurity (D0) affected by a lateral electric field in a parabolic quantum dot (QD). The results show that the electron and the hole ground-state energy and the band to band transition energi...

Rate coefficients for electron impact excitation, de-excitation, and total depopulation of the excited ions Co(XVII) up to Br(XXV) of the sodium isoelectronic sequence are calculated according to the analytical formulas of Vriens and Smeets. A simple modification has been made by substituting effective quantum numbers in Vriens' formulas to be appl...

Gain coefficients have been calculated for transitions of singlet levels ns–np of orbital n=4 and n=5 in magnesium-like ions with atomic numbers Z=18, 19, 20, 21, 22 and 23. Population inversions for 4p and 5p levels in these ions were also calculated, via electron collisional excitation, for electron temperature range of 93–231 eV and electron den...

In the present work we study the effect of the laser beam energy on the properties of the plasma generated by focusing an intense laser beam on Al solid target in air at atmospheric pressure. Plasma is generated using a Nd:YAG pulsed laser at 1064 nm wavelength, 6 ns pulse duration with a maximum pulse energy of 750mJ. The emission spectrum is col...

The 1st Joint (Host Laboratory) Experiment on laser plasma involving more than twenty scientists from eight countries has been carried out at the Laser and New Materials Laboratory, Faculty of Science, Cairo University, Egypt. It was co-ordinated by the International Atomic Energy Agency (IAEA) and supported through the IAEA and the ICTP (Internati...

Characteristics of argon plasma waveguide produced by alumina capillary discharge for short wavelength laser application J. Appl. Phys. 111, 093302 (2012) Synergetic effects of double laser pulses for the formation of mild plasma in water: Toward non-gated underwater laser-induced breakdown spectroscopy J. Chem. Phys. 136, 174201 (2012) Analysis of...

Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the “endothelial” cells, factor VIII-associated protein was demonstrated by indirect...

We have calculated fine-structure energy levels, oscillator strengths and transition probabilities for transitions among the terms belonging to the 1s22s22p6ns (2S), 1s22s22p6np (2P), 1s22s22p6nd (2D) (n = 3, 4, 5), and 1s22s22p6nf (2F) (n = 4, 5) configurations. The calculations are based upon the general configuration-interaction code CIV3 of Hib...

Some of the main functions of the arterial wall are fulfilled by the extracellular matrix of this tissue: tensile strength and elasticity to withstand the pulsating blood stream and filtration functions in regulating the transport between blood and tissues. This extracellular matrix is composed of a variety of different macromolecular components. T...

Tissue specimens from human fibrotic liver obtained by needle biopsy were cultured. Two cell types emerged from the tissue explants. From their morphology and biosynthetic products they resembled smooth muscle cells and endothelial cells from blood vessel walls. In the "endothelial" cells, factor VIII-associated protein was demonstrated by indirect...

The distribution of collagen type I and III and of the basement membrane collagens type IV and alphaA (alphaB)2 in normal and fibrotic human livers has been studied by indirect immunofluorescence using type specific antibodies. Collagens type I as well as type III are present in normal livers in the blood vessel walls and the wall of biliary ducts...

Fibronectin was detected by indirect immunofluorescence on primary cultures of rat hepatocytes maintained in the presence or absence of fetal calf serum. [14C]-Fibronectin synthesized in the presence of [14C]-glycine was isolated by immunoprecipitation and visualized by fluorography.

Smooth muscle cells were grown from explants of the tunica media of fetal and adult human aorta. Collagen was isolated after incubation with [14C]glycine and was characterized by ion-exchange chromatography. All cells investigated synthesized two types of collagen: Type I (chain composition [alpha1(I)]2alpha2) and type III (chain composition [alpha...