A5003374647- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- X-ray Spectroscopy and Fluorescence Analysis
- Cosmology and Gravitation Theories
- Advanced X-ray Imaging Techniques
- Mechanics and Biomechanics Studies
- Particle Accelerators and Free-Electron Lasers
- Black Holes and Theoretical Physics
- History and Developments in Astronomy
- Adaptive optics and wavefront sensing
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Relativity and Gravitational Theory
- Electron and X-Ray Spectroscopy Techniques
University of Arkansas at Fayetteville
2016-2025
Goddard Space Flight Center
2010-2024
Jet Propulsion Laboratory
2024
Johns Hopkins University
2010-2016
University of Baltimore
2015
Durham University
2008-2012
Pennsylvania State University
2003-2009
Leiden University
2009
Texas A&M University
2009
Columbia University
2009
[abridged] We present point-source catalogs for the 4Ms Chandra Deep Field-South (CDF-S), which is deepest survey to date and covers an area of 464.5 arcmin^2. provide a main source catalog, contains 740 X-ray point sources that are detected with wavdetect at false-positive probability threshold 1E-5 also satisfy binomial-probability source-selection criterion P<0.004; this approach designed maximize number reliable detected. A total 300 main-catalog new compared previous 2Ms CDF-S sources....
We present partial-correlation analyses that examine the strengths of relationships between l2500 Å, l2 keV, αOX, and redshift for optically selected active galactic nuclei (AGNs). extend work Strateva coworkers, which analyzed AGNs from Sloan Digital Sky Survey (SDSS), by including 52 moderate-luminosity, COMBO-17 survey with corresponding deep (≈250 ks to 1 Ms) X-ray observations Extended Chandra Deep Field-South. The extends ∼3 mag deeper than SDSS probes moderate-luminosity numerically...
We present X-ray source catalogs for the $\approx7$ Ms exposure of Chandra Deep Field-South (CDF-S), which covers a total area 484.2 arcmin$^2$. Utilizing WAVDETECT initial detection and ACIS Extract photometric extraction significance assessment, we create main catalog containing 1008 sources that are detected in up to three bands: 0.5-7.0 keV, 0.5-2.0 2-7 keV. A supplementary is also provided including 47 lower-significance have bright ($K_s\le23$) near-infrared counterparts. identify...
We describe the results of an extremely deep, 0.28 deg2 survey for z = 3.1 Lyα emission-line galaxies in Extended Chandra Deep Field-South. By using a narrowband 5000 Å filter and complementary broadband photometry from MUSYC survey, we identify statistically complete sample 162 with monochromatic fluxes brighter than 1.5 × 10-17 ergs cm-2 s-1 observer's frame equivalent widths greater 80 Å. show that width distribution these objects follows exponential rest-frame scale length w0 76 In...
We present new Chandra observations that complete a sample of seventeen (17) luminous infrared galaxies (LIRGs) with D < 60 Mpc and low Galactic column densities N_H 5 X 10^20 cm^-2. The LIRGs in our have total (8-1000um) luminosities the range L_IR ~ (1-8) 10^11 L_sol. high-resolution imaging X-ray spectral information from allow us to measure separately contributions active galactic nuclei (AGNs) normal galaxy processes (e.g., binaries hot gas). utilized plus UV estimate star-formation...
Abstract Modern and future surveys effectively provide a panchromatic view for large numbers of extragalactic objects. Consistently modeling these multiwavelength survey data is critical but challenging task studies. The Code Investigating GALaxy Emission ( cigale ) an efficient python code spectral energy distribution (SED) fitting galaxies active galactic nuclei (AGNs). Recently, major extension (named x-cigale has been developed to account AGN/galaxy X-ray emission improve AGN at UV-to-IR...
We present point-source catalogs for the ~2 Ms exposure of Chandra Deep Field-South (CDF-S); this is one two most-sensitive X-ray surveys ever performed. The survey covers an area ~436 arcmin^2 and reaches on-axis sensitivity limits ~1.9x10^{-17} ~1.3x10^{-16} ergs/cm^2/s 0.5-2.0 2-8 keV bands, respectively. Four hundred sixty-two point sources are detected in at least three bands that were searched; 135 these new compared to previous ~1 CDF-S detections. Source positions determined using...
We present Chandra point-source catalogs for the Extended Deep Field-South (E-CDF-S) survey. The E-CDF-S consists of four contiguous 250 ks observations covering an approximately square region total solid angle ≈0.3 deg2, which flank existing ≈1 Ms (CDF-S). survey reaches sensitivity limits ≈1.1 × 10-16 and ≈6.7 ergs cm-2 s-1 0.5-2.0 2-8 keV bands, respectively. detect 762 distinct X-ray point sources within exposure; 589 these are new (i.e., not previously detected in CDF-S). This brings...
We extend color–magnitude relations for moderate-luminosity X-ray active galactic nucleus (AGN) hosts and non-AGN galaxies through the galaxy formation epoch (z ≈ 1–4) in Chandra Deep Field-North Field-South (CDF-N CDF-S, respectively; jointly CDFs) surveys. This study was enabled by deepest available data from 2 Ms CDF surveys as well complementary ultradeep multiwavelength these regions. utilized analyses of diagrams (CMDs) to assess role AGNs evolution. First, we confirm some previous...
We present 0.5–2 keV, 2–8 4–8 and 0.5–8 keV (hereafter soft, hard, ultra-hard, full bands, respectively) cumulative differential number-count (log N–log S) measurements for the recently completed ≈4 Ms Chandra Deep Field-South (CDF-S) survey, deepest X-ray survey to date. implement a new Bayesian approach, which allows reliable calculation of number counts down flux limits that are factors ≈1.9–4.3 times fainter than previously investigations. In soft band (SB), most sensitive bandpass in...
X-ray photons, because of their long mean-free paths, can easily escape the galactic environments where they are produced, and interact at distances with intergalactic medium, potentially having a significant contribution to heating reionization early universe. The two most important sources photons in universe active nuclei (AGNs) binaries (XRBs). In this Letter we use results from detailed, large scale population synthesis simulations study energy feedback XRBs, first galaxies (z ∼ 20)...
High redshift galaxies permit the study of formation and evolution X-ray binary populations on cosmological timescales, probing a wide range metallicities star-formation rates. In this paper, we present results from large scale population synthesis that models first universe until today. We use as input to our modeling Millennium II Cosmological Simulation updated semi-analytic galaxy catalog by Guo et al. (2011) self-consistently account for star history metallicity universe. Our modeling,...
We present the results of a program to acquire high-quality optical spectra X-ray sources detected in E-CDF-S and its central area. New spectroscopic redshifts are measured for 283 counterparts Chandra with deep exposures (t~2-9 hr per pointing) using multi-slit facilities on both VLT Keck thus bringing total number spectroscopically-identified over 500 this survey field. provide comprehensive catalog including near-infrared counterparts, (both photometric) that incorporate published...
We investigate the population of high-redshift ($3\leq z < 6$) AGN selected in two deepest X-ray surveys, 7 Ms \textit{Chandra} Deep Field-South and 2 Field-North. Their outstanding sensitivity spectral characterization faint sources allow us to focus on sub-$L_*$ regime (log$L_{\mathrm{X}}\lesssim44$), poorly sampled by previous works using shallower data, obscured population. Taking fully into account individual photometric-redshift probability distribution functions, final sample consists...
[Abridged] We present reliable multiwavelength identifications and high-quality photometric redshifts for the 462 X-ray sources in ~2 Ms Chandra Deep Field-South. Source are carried out using deep optical-to-radio catalogs, then combined to create lists of primary secondary counterparts sources. identified 446 (96.5%) sources, with an expected false-match probability ~6.2%. A likelihood-ratio method is used source matching, which effectively reduces at faint magnitudes compared a simple...
We investigate the relation between total X-ray emission from star-forming galaxies and their star formation activity. Using nearby late-type ULIRGs Paper I Chandra Deep Fields, we construct a sample of 66 spanning redshift range z~0-1.3 star-formation rate (SFR) ~0.1-10^3 M_sun/yr. In agreement with previous results, find that Lx-SFR is consistent linear law both at z=0 for z=0.1-1.3 CDF galaxies, within statistical accuracy ~0.1 in slope relation. For sample, scaling Lx/SFR~(4.0\pm...
The large gas and dust reservoirs of submm galaxies (SMGs) could potentially provide ample fuel to trigger an Active Galactic Nucleus (AGN), but previous studies the AGN fraction in SMGs have been controversial largely due inhomogeneity limited angular resolution available submillimeter surveys. Here we set improved constraints on X-ray properties with ALMA Chandra observations Extended Deep Field-South (E-CDF-S). This study is first among similar works unambiguously identified counterparts...
We report the results of 15 × 3' mapping at 1.1 mm with Atacama Large Millimeter/submillimeter Array toward central region z = 3.09 SSA22 protocluster. By combining our source catalog archival spectroscopic redshifts, we find that eight submillimeter galaxies (SMGs) flux densities, S1.1 0.7–6.4 mJy (LIR ∼ 1012.1–1013.1 L⊙) are 3.08–3.10. Not only these SMGs members protocluster, but they in fact reside within node junction 50 Mpc scale filamentary three-dimensional structure traced by Lyα...
We present new Chandra constraints on the X-ray luminosity functions (XLFs) of binary (XRB) populations, and their scaling relations, for a sample 38 nearby galaxies (D = 3.4-29 Mpc). Our galaxy is drawn primarily from Spitzer infrared survey (SINGS), contains wealth (5.8 Ms total) multiwavelength data, allowing star-formation rates (SFRs) stellar masses (M*) to be measured subgalactic scales. divided 2478 detected sources into 21 subsamples in bins specific-SFR (sSFR SFR/M*) constructed...
We present measurements of the evolution normal-galaxy X-ray emission from $z \approx$ 0-7 using local galaxies and galaxy samples in 6 Ms Chandra Deep Field-South (CDF-S) survey. The majority CDF-S are observed at rest-frame energies above 2 keV, where is expected to be dominated by binary (XRB) populations; however, hot gas provide small contributions observed- frame < 1 keV 1$. show that a single scaling relation between luminosity ($L_{\rm X}$) star-formation rate (SFR) insufficient for...
Abstract In the present-day universe, most massive galaxies are ellipticals located in cores of galaxy clusters, harboring heaviest super-massive black holes (SMBHs). However, mechanisms that drive early growth phase and subsequent transformation morphology kinematics remain elusive. Here we report (sub)kiloparsec-scale observations stars, gas, dust ADF22.A1, a bright dusty starburst at $z=3.1$, hosting heavily obscured active galactic nucleus residing proto-cluster core. ADF22.A1 is giant...
We investigate the multiwavelength emission of BzK-selected star-forming galaxies at z ~ 2 in Great Observatories Origins Deep Survey (GOODS) North region. Most (82%) sources are individually detected 24 μm Spitzer MIPS imaging, and one-fourth (26%) VLA radio data. Significant detections undetected objects obtained through stacking radio, submillimeter, X-ray domains. The typical galaxy with stellar mass ~1011 M☉ = is an ultraluminous infrared (ULIRG), LIR (1-2) × 1012 L☉ star formation rate...
We present an analysis of 109 moderate-luminosity (41.9 ⩽ log L0.5–8.0 keV 43.7) AGNs in the Extended Chandra Deep Field-South survey, which is drawn from 5549 galaxies COMBO-17 and GEMS surveys having 0.4 z⩽ 1.1. These obscured or optically weak facilitate study their host since provide insubstantial amount contamination to galaxy light. find that color distribution AGN highly dependent on (1) strong color-evolution luminous (MV < − 20.7) galaxies, (2) influence ~10 Mpc scale structures....
We present the results of a 400 ks Chandra survey 29 extended Lyα emitting nebulae (Lyα Blobs, LABs) in z = 3.09 protocluster SS A22 field. detect luminous X-ray counterparts five LABs, implying large fraction active galactic nuclei (AGN) fAGN 17+12−7% down to L2–32 keV ∼ 1044 erg s−1. All AGN appear be heavily obscured, with spectral indices obscuring column densities NH > 1023 cm−2. The should considered lower limit, since several more LABs not detected show signatures their mid-infrared...
We report on the identification of highest redshift submillimetre-selected source currently known LESS J033229.4−275619. This was detected in Large Apex Bolometer Camera (LABOCA) Extended Chandra Deep Field-South (ECDF-S) Submillimetre Survey (LESS), a sensitive 870-μm survey (σ870 μm∼ 1.2 mJy) full 30 × arcmin2 ECDF-S with LABOCA Atacama Pathfinder Experiment telescope. The submillimetre emission is identified radio counterpart for which optical spectroscopy provides z= 4.76. show that...