A5086826935- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Particle Detector Development and Performance
- Pulsars and Gravitational Waves Research
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Relativity and Gravitational Theory
- Cosmology and Gravitation Theories
- Scientific Computing and Data Management
- Calibration and Measurement Techniques
- Mechanics and Biomechanics Studies
- Radio Astronomy Observations and Technology
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Scientific Measurement and Uncertainty Evaluation
- High-pressure geophysics and materials
Johns Hopkins University
2013-2024
Goddard Space Flight Center
2015-2024
Northrop Grumman (United States)
2024
Massachusetts Institute of Technology
2016-2022
Center for Astrophysics Harvard & Smithsonian
2019-2022
Pennsylvania State University
2019
Smithsonian Astrophysical Observatory
2016-2017
Michigan United
2017
University of Michigan–Ann Arbor
2017
Friedrich-Alexander-Universität Erlangen-Nürnberg
2016
We present the first public version (v0.2) of open-source and community-developed Python package, Astropy. This package provides core astronomy-related functionality to community, including support for domain-specific file formats such as Flexible Image Transport System (FITS) files, Virtual Observatory (VO) tables, common ASCII table formats, unit physical quantity conversions, constants specific astronomy, celestial coordinate time transformations, world system (WCS) support, generalized...
The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates band from 3 to 79 keV, extending sensitivity of far beyond ∼10 keV cutoff achieved by all previous satellites. inherently low background associated with concentrating light enables probe hard sky a more than 100-fold improvement over collimated or coded mask instruments that have operated this bandpass. Using its unprecedented...
Abstract We have developed a framework for the Monte Carlo simulations of X-Ray Telescope (XRT) and X-ray Imaging Spectrometer (XIS) on board Suzaku, mainly scientific analysis spatially spectroscopically complex celestial sources. A photon-by-photon instrumental simulator is built ANL platform, which has been successfully used in ASCA data analysis. The modular structure, XRT simulation based ray-tracing library, while XIS utilizes spectral “Redistribution Matrix File” (RMF), generated...
ABSTRACT We report the detection of coherent pulsations from ultraluminous X-ray source (ULX) NGC 7793 P13. The ≈0.42 s nearly sinusoidal were initially discovered in broadband observations using XMM-Newton and NuSTAR taken 2016. subsequently also found archival data 2013 2014. significant (≫5 σ ) demonstrates that compact object P13 is a neutron star, given observed peak luminosity ≈10 40 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>erg</mml:mi>...
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...
We report on the first deep X-ray survey with XMM-Newton observatory during performance verification phase. The field of Lockman Hole, one best studied sky areas over a very wide range wavelengths, has been observed. A total ~100 ksec good exposure time accumulated. Combining images European Photon Imaging Camera (EPIC) detectors we reach flux limit 0.31, 1.4 and , respectively in 0.5-2, 2-10, 5-10 keV band. Within an off-axis angle 10 arcmin detect 148, 112 61 sources, respectively....
In this paper we assess the relationship of population Active Galactic Nuclei (AGN) selected by hard X-rays to traditional AGN with strong optical emission lines. First, study emission-line properties a new X-ray sample 47 local (classified optically as both Type 1 and 2 AGN). We find that X- ray (3-20 keV) [OIII]$λ$5007 luminosities are well-correlated over range about four orders-of-magnitude in luminosity (mean ratio 2.15 dex standard deviation $σ$ = 0.51 dex). Second, 55 from literature...
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...
We analyzed 1441 Chandra X-ray point sources in 32 nearby galaxies. The total point-source luminosity L_XP is well correlated with B, K, and FIR+UV luminosities of spiral host galaxies, the B K for ellipticals. This suggests an intimate connection between both old young stellar populations, which are proxies galaxy mass M star-formation rate SFR. derive proportionality constants 1.3E29 erg/s/Msol 0.7E39 erg/s/(Msol/yr), can be used to estimate components from SFR, respectively. cumulative...
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 NuSTAR and XMM-Newton observations two ultraluminous X-ray sources (ULX) NGC 1313 X-1 X-2. The combined spectral bandpass satellites enables us to produce first spectrum between 0.3 30 keV, while X-2 is not significantly detected by above 10 keV. data demonstrate that has a clear cutoff whose presence was only marginally detectable with previous observations. This rules out interpretation as black hole in standard low/hard state, it deeper than predicted for...
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 results from the coordinated broadband X-ray observations of extreme ultraluminous source Holmberg IX X-1 performed by NuSTAR, XMM-Newton and Suzaku in late 2012. These provide first high-quality spectra above 10 keV to date, extending coverage this remarkable up ~30 keV. Broadband were undertaken at two epochs, between which exhibited both flux strong spectral variability, increasing luminosity Lx = (1.90+/-0.03)e40 erg/s (3.35+/-0.03)e40 erg/s. Neither epoch exhibits a spectrum...
The Advanced X-ray Imaging Satellite (AXIS) is a Probe-class concept that will build on the legacy of Chandra Observatory by providing low-background, arcsecond-resolution imaging in 0.3-10 keV band across 450 arcminute$^2$ field view, with an order magnitude improvement sensitivity. AXIS utilizes breakthroughs construction lightweight segmented optics using single-crystal silicon, and developments fabrication large-format, small-pixel, high readout rate CCD detectors good spectral...
Abstract In this Letter, we report the discovery of highest redshift, heavily obscured, radio-loud (RL) active galactic nucleus (AGN) candidate selected using JWST NIRCam/MIRI, mid-IR, submillimeter, and radio imaging in COSMOS-Web field. Using multifrequency observations mid-IR photometry, identify a powerful, RL, growing supermassive black hole with significant spectral steepening energy distribution ( f 1.28 GHz ∼ 2 mJy, q 24 μ m = −1.1, α 1.28−3 − 1.2, Δ 0.4). conjunction ALMA, deep...
We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using the Advanced CCD Imaging Spectrometer on board Chandra X-Ray Observatory. The total sample consists 41 low-luminosity active galactic nuclei (AGNs), including Seyfert galaxies, LINERs, and LINER/H II transition objects. In initial subsample 24 objects observed thus far, we detect in ~62% a compact, pointlike source astrometrically coincident with either optical or radio position nucleus. high...
ROSAT, and now Chandra, X-ray images allow studies of extranuclear point sources in galaxies other than our own. observations normal with ROSAT Chandra have revealed that off-nuclear, compact, Intermediate-luminosity (Lx[2-10 keV] >= 1e39 erg/s) Objects (IXOs, a.k.a. ULXs [Ultraluminous sources]) are quite common. Here we present a catalog finding charts for 87 IXOs 54 galaxies, derived from all the HRI imaging data cz <= 5000 km/s Third Reference Catalog Bright Galaxies (RC3). We...
This paper presents a comprehensive study of the X-ray properties low-ionization nuclear emission-line regions (LINERs) and low-luminosity Seyfert galaxies based on observations obtained with ASCA satellite. We analyzed data 53 21 LINERs 17 Seyferts. emission has been detected in all but one object. The luminosities 2-10 keV band range from 4 × 1039 to 5 1041 ergs s-1, which are 1-3 orders magnitude smaller than classical galaxies. spectra most objects well described by canonical model...
We present initial results from a Chandra survey of complete sample the 8 nearest (z <= 0.04) ultraluminous IR galaxies (ULIRGs), and also include IR-luminous galaxy NGC 6240 for comparison. In this paper we use hard X-rays (2-8 kev) to search possible presence an obscured AGN. every case, X-ray source is detected in nuclear region. If divide according optical/IR spectroscopic classification (starburst vs. AGN), find that 5 ``starburst'' ULIRGs have luminosities about order-of-magnitude...
We present HST UV/optical imaging, Spitzer mid-IR photometry, and optical spectroscopy of a sample 30 low-redshift (z=0.1-0.3) galaxies chosen from SDSS/GALEX to be accurate local analogs the high-z Lyman Break Galaxies. The Analogs (LBAs) are similar in mass, metallicity, dust, SFR, size gas velocity dispersion, thus enabling detailed investigation processes that important at high-z. emission line properties LBAs also those LBGs, indicating comparable conditions their ISM. In UV,...
We present high-energy (3–30 keV) NuSTAR observations of the nearest quasar, ultraluminous infrared galaxy (ULIRG) Markarian 231 (Mrk 231), supplemented with new and simultaneous low-energy (0.5–8 data from Chandra. The source was detected, though at much fainter levels than previously reported, likely due to contamination in large apertures previous non-focusing hard X-ray telescopes. full band (0.5–30 spectrum suggests active galactic nucleus (AGN) Mrk is absorbed by a patchy Compton-thin...
We present Nustar 3-40 keV observations of the optically selected Type 2 quasar (QSO2) SDSS J1034+6001 or Mrk 34. The high-quality hard X-ray spectrum and archival XMM-Newton data can be fitted self-consistently with a reflection-dominated continuum strong Fe Kalpha fluorescence line equivalent-width >1 keV. Prior spectral fitting below 10 showed source to consistent being obscured by Compton-thin column densities gas along line-of-sight, despite evidence for much higher columns from...
We present a Nuclear Spectroscopic Telescope Array (NuSTAR), Chandra, and XMM-Newton survey of nine the nearest ultraluminous infrared galaxies (ULIRGs). The unprecedented sensitivity NuSTAR at energies above 10 keV enables spectral modeling with far better precision than was previously possible. Six sources observed were detected sufficiently well by to model in detail their broadband X-ray spectra, recover levels obscuration intrinsic luminosities. Only one source (IRAS 13120–5453) has...
ABSTRACT Using the Chandra Source Catalog 2.0 and a newly compiled catalogue of galaxies in local Universe, we deliver census ultraluminous X-ray source (ULX) populations nearby galaxies. We find 629 ULX candidates 309 with distance smaller than 40 Mpc. The foreground/background contamination is $\sim \! 20{{\ \rm per\ cent}}$. bona fide star-forming scale on average star formation rate stellar mass (M⋆) such that number ULXs per galaxy $0.45^{+0.06}_{-0.09}\times \frac{\rm SFR}{\rm M_\odot...
We present a detailed, broadband X-ray spectral analysis of the ULX pulsar NGC 7793 P13, known super-Eddington source, utilizing data from $XMM$-$Newton$, $NuSTAR$ and $Chandra$ observatories. The $XMM$-$Newton+NuSTAR$ spectrum P13 is qualitatively similar to rest sample with coverage, suggesting that additional ULXs in population may host neutron star accretors. Through time-averaged, phase-resolved multi-epoch studies, we find two non-pulsed thermal blackbody components temperatures...