D. J. Burke
A5035705826- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Particle Detector Development and Performance
- Computational Physics and Python Applications
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- History and Developments in Astronomy
- Pulsars and Gravitational Waves Research
- Scientific Computing and Data Management
- Particle physics theoretical and experimental studies
- Infrared Target Detection Methodologies
- Particle Accelerators and Free-Electron Lasers
- Parallel Computing and Optimization Techniques
- Distributed and Parallel Computing Systems
- Advanced Measurement and Detection Methods
- Adaptive optics and wavefront sensing
- Statistical and numerical algorithms
- Radio Astronomy Observations and Technology
- Mathematical and Theoretical Analysis
Center for Astrophysics Harvard & Smithsonian
2010-2024
Embry–Riddle Aeronautical University
2018
Smithsonian Astrophysical Observatory
2006-2018
Infosys (India)
2014
Harvard University
2002-2007
Direction des énergies
2007
CEA Paris-Saclay
2007
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2007
Sheffield Children's Hospital
2006
The University of Texas at Austin
2006
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...
Abstract The Astropy Project supports and fosters the development of open-source openly developed Python packages that provide commonly needed functionality to astronomical community. A key element is core package astropy , which serves as foundation for more specialized projects packages. In this article, we summarize features in recent major release, version 5.0, updates on Project. We then discuss supporting a broader ecosystem interoperable packages, including connections with several...
Abstract The Astropy Project supports and fosters the development of open-source openly developed Python packages that provide commonly needed functionality to astronomical community. A key element is core package astropy , which serves as foundation for more specialized projects packages. In this article, we an overview organization project summarize features in package, recent major release, version 2.0. We then describe infrastructure designed facilitate support a broader ecosystem...
The CIAO (<i>Chandra</i> Interactive Analysis of Observations) software package was first released in 1999 following the launch <i>Chandra</i> X-ray Observatory and is used by astronomers across world to analyze data as well from other telescopes. From earliest design discussions, planned a general-purpose scientific analysis system optimized for astronomy, consists mainly command line tools (allowing easy pipelining scripting) with parameter-based interface layered on flexible manipulation...
We use Chandra data to map the gas temperature in central region of merging cluster A2142. The is markedly nonisothermal; it appears that cooling flow has been disturbed but not destroyed by a merger. X-ray image exhibits two sharp, bow-shaped, shock-like surface brightness edges or density discontinuities. However, and pressure profiles across these indicate are shock fronts. reasonably continuous edges, while entropy jumps opposite sense (i.e. denser side edge lower temperature, hence...
We describe the properties of a sample galaxy groups with very unusual distributions luminosities. The most extreme example has an X-ray luminosity similar to that Virgo cluster but low richness, only one brighter than L*, compared six in Virgo. That galaxy, however, is optically more luminous any and optical as bright many central cD galaxies rich Abell clusters. characteristic feature fossil we study light arises from dominant, galaxy. define system and, based on this definition, construct...
Abstract The Chandra Source Catalog (CSC) is a virtual X-ray astrophysics facility that enables both detailed individual source studies and statistical of large samples sources detected in Advanced CCD Imaging Spectrometer High Resolution Camera-I imaging observations obtained by the Observatory. catalog provides carefully curated, high-quality, uniformly calibrated analyzed tabulated positional, spatial, photometric, spectral, temporal properties, as well science-ready data products. latter...
We present the Bright SHARC (Serendipitous High-Redshift Archival ROSAT Cluster) Survey, which is an objective search for serendipitously detected extended X-ray sources in 460 deep PSPC pointings. The Survey covers area of 178.6 deg2 and has yielded 374 sources. discuss data reduction, candidate selection results from our on-going optical follow-up campaign. concentrates on brightest 94 now 97% complete. have identified 37 clusters galaxies, we redshifts luminosities. span a redshift range...
We report on a 20 ks XMM observation of the distant cluster , discovered at in SHARC survey. The has regular spherical morphology, suggesting it is relaxed state. combined fit EPIC/MOS&pn camera gives mean temperature with an iron abundance . profile, measured for first time such redshift, consistent isothermal atmosphere up to half virial radius. surface brightness nearly radius, well fitted by and core radius compared properties nearby clusters two cosmological models: Einstein–de Sitter...
We use Chandra data to derive a detailed gas temperature map of the nearby, hot, merging galaxy cluster A754. Combined with X-ray and optical images, reveals more complex merger geometry than previously thought, possibly involving two subclusters or cool cloud sloshing independently from its former host subcluster. In central region, we detect spatial variations on all linear scales, 100 kpc (the resolution) up, which likely remain shock passage. These are used an upper limit effective...
Observations of young open clusters show a bimodal distribution rotation periods that has been difficult to explain with existing stellar spin-down models. Detailed MHD wind simulations have demonstrated surface magnetic field morphology strong influence on wind-driven angular momentum loss. suggest faster rotating stars store larger fraction their flux in higher-order multipolar components the field. In this work, we present new model for that, first time, accounts configuration. We how...
We investigate the evolution of universal rest-frame ultraviolet luminosity density from z = 1.5 to present. analyze an extensive sample multicolor data (U, BAB, VAB 24.5) plus spectroscopic redshifts Hawaii Survey Fields and Hubble Deep Field. Our allow us select our in (2500 Å) over entire redshift range 1.5. conclude that is a function form (1 + z)1.7 ± 1.0 for flat lambda (Ωm0 0.3, Ωλ0 0.7) cosmology z)2.4 Einstein–de Sitter cosmology.
Abstract We present an examination of the kinematics and stellar populations a sample three brightest group galaxies (BGGs) cluster (BCGs) in X-ray groups clusters. have obtained high signal-to-noise ratio Gemini/Gemini South Multi-Object Spectrograph (GMOS) long-slit spectra these use Lick indices to determine ages, metallicities α-element abundance ratios out at least their effective radii. find that BGGs BCGs very uniform masses, central ages metallicities. Examining radial dependence...
Abstract We examine the central galaxy luminosity–host halo mass relation for 54 brightest group galaxies (BGGs) and 92 cluster (BCGs) at z &lt; 0.1 present first measurement of this a sample known BCGs . At we find LK∝M0.24±0.08200 early-type BGGs in groups with extended X-ray emission LK∝M0.11±0.10200 alone. 0.8 LK∝M0.28±0.11200. conclude that there is no evidence evolution relationship between 0.8: BCG growth appears to still be limited by time-scale dynamical friction these earlier...
We present the first results from a new, deep (200 ks) Chandra observation of X-ray luminous galaxy cluster surrounding powerful (L ∼ 1047 erg s−1), high-redshift (z = 1.067), compact-steep-spectrum radio-loud quasar 3C 186. The diffuse emission has roughly ellipsoidal shape and extends out to radii at least ∼60 arcsec (∼500 kpc). centroid is offset by 0.68 ± 011 (∼5.5 0.9 kpc) position quasar. measure mass within radius which mean enclosed density 2500 times critical density, r2500...
This Resource Book reviews the physics opportunities of a next-generation e+e- linear collider and discusses options for experimental program. Part 1 contains table contents introduction gives summary case 500 GeV collider.
The H2O Southern Galactic Plane Survey (HOPS) has mapped 100 square degrees of the plane for water masers and thermal molecular line emission using 22-m Mopra telescope. We describe automated spectral-line fitting pipelines used to determine properties detected in HOPS datacubes, use these derive physical kinematic gas survey. A combination angular resolution, sensitivity, velocity resolution high critical density lines targeted make data cubes ideally suited finding precursor clouds most...
Improving door-to-needle times (DNTs) for thrombolysis of acute ischemic stroke patients improves outcomes, but participation in DNT improvement initiatives has been mostly limited to larger, academic medical centers with an existing interest quality improvement. It is not known whether can improve at a population level, including smaller community hospitals. This study aims determine the effect provincial collaborative intervention on and patient outcomes.A pre post cohort was conducted...
From the Press-Schechter mass function and empirical X-ray cluster luminosity-temperature (L-T) relation, we construct an luminosity that can be applied to growing number of high-redshift, catalogs constrain cosmological parameters. In this paper, apply Einstein Medium Sensitivity Survey (EMSS) ROSAT Brightest Cluster Sample (BCS) value Omega_m. case EMSS, find a factor 4 - 5 fewer clusters at redshifts above z = 0.4 than below redshift luminosities L_X 7 x 10^44 erg s^-1 (0.3 3.5 keV),...
We present the z = 0.3-0.7 cluster X-ray luminosity function (XLF) determined from Southern Serendipitous High-Redshift Archival ROSAT Cluster (SHARC) survey. Over range L ~ (0.3-3) × 1044 ergs s-1 (0.5-2.0 keV), XLF is in close agreement with that of low-redshift population. This result greatly strengthens our previous claim no evolution population, at these luminosities, a median redshift z=0.44.
We report on the first results from a redshift survey of flux-limited sample X-ray clusters selected serendipitously ROSAT PSPC data archive. spectroscopically confirm 15 in range 0.3 < z 0.7, to flux limit ≃3.9 × 10-14 ergs s-1 cm-2, over area 17.2 deg2. The surface density our is 2.0+ 0.4−0.3 deg-2, good agreement with number cluster candidates detected using algorithms designed search for very extended sources. between 0.7 consistent prediction based simple extrapolation local luminosity...
We present results from a Chandra X-Ray Observatory study of the field X-ray source populations in four different observations: two high-redshift (z ~ 0.5) clusters galaxies 3C 295 and RX J003033.2+261819; noncluster fields with similar exposure time. Surprisingly, 0.5-2 keV surface densities (~900-1200 sources deg-2 at flux limit 1.5 × 10-15 ergs cm-2 s-1) measured an ~8' 8' area surrounding each cluster exceed by factor ~2 value expected on basis ROSAT log N- S, significance σ each, or...
We describe XMM-Newton Guaranteed Time observations of a sample eight high redshift clusters. The goal these was to measure the luminosity and temperature clusters precision ~10%, leading constraints on possible evolution luminosity-temperature () relation, ultimately values matter density, , and, lesser extent, cosmological constant . were drawn from SHARC 160 Square Degree (160SD) ROSAT surveys span bolometric (0.0–20 keV) range 2.0 erg s-1 (, ). Here we our data analysis techniques...
Abstract Since its discovery in 2008, the Andromeda galaxy nova M31N 2008-12a has been observed eruption every single year. This unprecedented frequency indicates an extreme object, with a massive white dwarf and high accretion rate, which is most promising candidate for single-degenerate progenitor of Type Ia supernova known to date. The previous three eruptions have displayed remarkably homogeneous multiwavelength properties: (i) from faint peak, optical light curve declined rapidly by two...