A5072413212- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Semiconductor Detectors and Materials
- Mechanics and Biomechanics Studies
- Relativity and Gravitational Theory
- Advanced X-ray Imaging Techniques
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
- Scientific Measurement and Uncertainty Evaluation
- Atomic and Subatomic Physics Research
- Geophysics and Sensor Technology
- Nuclear physics research studies
- Nuclear Physics and Applications
- Astro and Planetary Science
Johns Hopkins University
2016-2025
Goddard Space Flight Center
2016-2025
National Aeronautics and Space Administration
2025
Kavli Institute for Particle Astrophysics and Cosmology
2024
Massachusetts Institute of Technology
2024
Kyoto University
2022
University of Miyazaki
2022
Japan Aerospace Exploration Agency
2022
University of Alabama
2011-2013
University of Alabama in Huntsville
2006-2010
One hundred seven ultraluminous X-ray sources (ULXs) with 0.3–10.0 keV luminosities in excess of 1039 erg s−1 are identified a complete sample 127 nearby galaxies. The includes all galaxies within 14.5 Mpc above the completeness limits both Uppsala Galaxy Catalogue and Infrared Astronomical Satellite survey. galaxy spans Hubble types, four-decade range mass, 7.5 < log (M/M☉) 11.4, star formation rate, 0.0002 SFR(M☉ yr−1) ⩽ 3.6. ULXs detected this at rates one per 3.2 × 1010 M☉, ∼0.5 M☉ yr−1...
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}$) star-formation rate (SFR) insufficient for...
The Advanced X-ray Imaging Satellite (AXIS) is a Probe-class concept that will build on the legacy of Chandra Observatory by providing low-background, arcsecond-resolution imaging in 0.3-10 keV band across 450 arcminute$^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...
Gas undergoing Bondi accretion onto a supermassive black hole (SMBH) becomes hotter toward smaller radii. We searched for this signature with Chandra observation of the hot gas in NGC 3115, which optical observations show has very massive SMBH. Our analysis suggests that we are resolving, first time, flow within radius an temperature is rising galaxy center as expected all models gravitationally capturing ambient gas. There no hard central point source could cause such apparent rise...
The recent discovery by Bachetti et al. (2014) of a pulsar in M82 that can reach luminosities up to 10^40 ergs s^-1, factor ~100 the Eddington luminosity for 1.4 Msol compact object, poses challenge accretion physics. In order better understand nature this source and its duty cycle, light several physical models have been subsequently published, we conduct spectral temporal analysis 0.5-8 keV X-ray emission from 15 years Chandra observations. We fit spectra with power-law model disk black...
Observational confirmation of hot accretion model predictions has been hindered by the challenge to resolve spatially Bondi radii black holes with X-ray telescopes. Here, we use Megasecond Chandra Visionary Project (XVP) observation NGC~3115 supermassive hole place first direct observational constraints on and spectroscopically resolved structures emitting gas inside radius a hole. We measured temperature density profiles from fraction out tens (R_B = 2.4-4.8 arcsec 112-224 pc). The...
We have studied high mass X-ray binary (HMXB) populations within two low-metallicity, starburst galaxies, Haro 11 and VV 114. These galaxies serve as analogs to high-redshift (z>2) Lyman break the larger sample of (LBAs) are sufficiently nearby (<87 Mpc) be spatially-resolved by Chandra. Previous studies emission in LBAs found that 2-10 keV luminosity per star formation rate (SFR) these is elevated, potentially because their low metallicities (12+log[O/H]= 8.3-8.4). Theoretically,...
High-energy emission associated with star formation has been proposed as a significant source of interstellar medium (ISM) ionization in low-metallicity starbursts and an important contributor to the heating intergalactic (IGM) high-redshift ($z > 8$) Universe. Using Chandra observations sample 30 galaxies at $D \approx$~200--450 Mpc that have high specific star-formation rates 3--9 Gyr$^{-1}$ metallicities near $Z \approx 0.3 Z_\odot$, we provide new measurements average 0.5--8 keV...
Abstract We present a methodology for modeling the joint ionizing impact due to “simple X-ray population” (SXP) and its corresponding simple stellar population (SSP), where “simple” refers single age metallicity population. construct composite spectral energy distributions (SEDs) including contributions from ultraluminous sources stars, with physically meaningful consistent consideration of relative each component as function instantaneous burst metallicity. These SEDs are used input...
Deep Chandra ACIS observations of the region around putative pulsar, CXOU J061705.3+222127, in supernova remnant IC443 reveal an ~5$^{\prime\prime}$-radius ring-like structure surrounding pulsar and a jet-like feature oriented roughly north-south across ring through pulsar's location at 06$^{\rm h}$17$^{\rm m}$5.200$^{\rm s}$ +22$^{\circ}$21$^{\prime}$27.52$^{\prime\prime}$ (J2000.0 coordinates). The further confirm that (1) spectrum flux central object are consistent with rotation-powered...
We present nearly simultaneous Chandra and NuSTAR observations of two actively star-forming galaxies within 50 Mpc: NGC 3256 3310. Both are significantly detected by both NuSTAR, which together provide the first-ever spectra these spanning 0.3–30 keV. The X-ray emission from is spatially resolved Chandra; we find that hot gas dominates E < 1–3 keV while ultraluminous sources (ULXs) majority contributions to at > galaxy-wide follow steep power-law distributions with Γ ≈ 2.6 5–7 Using new...
Lyman Break Analogs (LBA) are local proxies of high-redshift Galaxies (LBG). Studies nearby starbursts have shown that continuum and line emission absorbed by dust the Lyman-alpha is resonantly scattered neutral hydrogen. A source feedback required to prevent scattering allow escape. There two X-ray point sources embedded in Analog galaxy Haro 11. 11 X-1 an extremely luminous (L$_{X} \sim 10^{41}$ ergs s$^{-1}$), spatially compact with a hard spectrum. similar extreme Black Hole Binary (BHB)...
Abstract We investigate X-ray binary (XRB) luminosity function (XLF) scaling relations for Chandra-detected populations of low-mass XRBs (LMXBs) within the footprints 24 early-type galaxies. Our sample includes Chandra and Hubble Space Telescope observed galaxies at Mpc that have estimates globular cluster (GC) specific frequency ( S N ) reported in literature. As such, we are able to directly classify X-ray-detected sources as being coincident with unrelated background/foreground objects,...
We present an analysis of the ultraluminous X-ray source (ULX) population in 75 Virgo cluster late-type galaxies, including all those with a star formation rate >~ 1 M_{sun}/yr and representative sample less star-forming ones. This study is based on 110 observations obtained over 20 years Chandra Observatory Advanced Camera for Imaging Spectroscopy. As part Large Program, new were 52 these galaxies. The data are complete to sensitivity about 10^{39} erg/s, typical detection limit 3 x 10^{38}...
Abstract We present L ightning , a new spectral energy distribution fitting procedure, capable of quickly and reliably recovering star formation history (SFH) extinction parameters. The SFH is modeled as discrete steps in time. In this work, we assumed lookback times 0–10 Myr, 10–100 0.1–1 Gyr, 1–5 5–13.6 Gyr. consists fully vectorized inversion algorithm to determine step intensities combines with grid-based approach three apply our procedure the extensive far-UV-to-far-IR photometric data...
We report on simultaneous observations of the local starburst system Arp 299 with NuSTAR and Chandra, which provides first resolved images this galaxy up to energies ~ 45 keV. Fitting 3-40 keV spectrum reveals a column density $N_{\rm H}$ 4 x10^{24} cm^{-2}, characteristic Compton-thick AGN, 10-30 luminosity 1.2x 10^{43} ergs s^{-1}. The hard X-rays detected by above 10 are centered western nucleus, 299-B, previous X-ray have shown be primary source neutral Fe-K emission. Other sources,...
Abstract Galactic winds are associated with intense star formation and active galactic nuclei. Depending on their mechanism velocity, they may remove a significant fraction of gas from host galaxies, thus suppressing formation, enriching the intergalactic medium, shaping circumgalactic gas. However, long-term evolution these remains mostly unknown. We report detection wind NGC 3079 to at least 60 kpc galaxy. detect in far-ultraviolet (FUV) line emission (as inferred broad FUV filter Galaxy...
Abstract Up to 40% of galaxies in the local Universe host a low-luminosity active galactic nucleus (LLAGN), making it vital understand this mode black hole accretion. However, presence or absence Seyfert-like geometries—an accretion disk close hole, an optical broad-line region, and molecular torus—remains uncertain owing low flux levels sources within class. Herein we present analysis XRISM/Resolve spectrum M81*, LLAGN heart nearby spiral galaxy M81. A weak, neutral Fe K emission line is...
We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect characterize point source three nearby early-type galaxies: NGC 3115, 3379, 3384. The luminosity-weighted ages our sample span 3-10 Gyr. population synthesis models predict that field LMXBs associated with younger should be more numerous luminous per unit mass than older...
Prior to the launch of NuSTAR, it was not feasible spatially resolve hard (E > 10 keV) emission from galaxies beyond Local Group. The combined NuSTAR data set, comprised three ∼165 ks observations, allows spatial characterization X-ray in galaxy NGC 253 for first time. As a follow up our initial study its nuclear region, we present results concerning full simultaneous Chandra, and Very Long Baseline Array monitoring local starburst 253. Above ∼10 keV, nearly all is concentrated within 100''...
The Advanced X-ray Imaging Satellite (AXIS), a concept recently submitted to NASA's Astrophysics Probe Explorer competition, will offer low-background, arcsecond-resolution imaging in the 0.3–10 keV band across 450-arcmin2 field of view, with an effective area at 1 least 4200 cm<sup>2</sup>. AXIS bring astronomy back forefront modern mainstream astrophysics, reaching equivalent depths X-rays many major facilities 2030's (e.g., JWST, Roman, Rubin, ngVLA, LISA) address most important questions...
Hinge clumps are luminous knots of star formation near the base tidal features in some interacting galaxies. We use archival Hubble Space Telescope UV/optical/IR images and Chandra X-ray maps along with GALEX UV, Spitzer IR, ground-based optical/near-IR to investigate forming properties a sample 12 hinge five The most extreme these have rates 1 - 9 M(sun)/yr, comparable or larger than `overlap' region intense between two disks colliding galaxy system Antennae. In HST images, we found...