A. Vikhlinin
A5043871279- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Cosmology and Gravitation Theories
- Adaptive optics and wavefront sensing
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- Advanced X-ray Imaging Techniques
- Radio Astronomy Observations and Technology
- History and Developments in Astronomy
- Particle Detector Development and Performance
- Superconducting and THz Device Technology
- Scientific Research and Discoveries
- X-ray Spectroscopy and Fluorescence Analysis
- Medical Imaging Techniques and Applications
- Statistical and numerical algorithms
- Advanced X-ray and CT Imaging
- Advanced Measurement and Metrology Techniques
- Dark Matter and Cosmic Phenomena
- Particle Accelerators and Free-Electron Lasers
Center for Astrophysics Harvard & Smithsonian
2015-2024
Space Research Institute
2014-2024
Smithsonian Astrophysical Observatory
2010-2022
Harvard University Press
2006-2019
Max Planck Institute for Astronomy
2019
Max Planck Society
2019
University of Chicago
2014
Russian Academy of Sciences
1994-2014
CFA Institute
1999-2013
Harvard University
1997-2012
We present gas and total mass profiles for 13 low-redshift, relaxed clusters spanning a temperature range 0.7-9 keV, derived from all available Chandra data of sufficient quality. In clusters, are measured to large radii (Vikhlinin et al.) so that direct hydrostatic estimates possible nearly r_500 or beyond. The density was accurately traced larger radii; its profile is not described well by beta-model, showing continuous steepening with radius. rho_tot their scaling generally follow the...
We compare new maps of the hot gas, dark matter, and galaxies for 1E 0657-56, a cluster with rare high-velocity merger occurring nearly in plane sky. The X-ray observations reveal bullet-like gas subcluster just exiting collision site. A prominent bow shock gives an estimate velocity, 4500 km s-1, which lies mostly optical image shows that lags behind galaxies. weak-lensing mass map reveals matter clump lying ahead collisional bullet but coincident effectively collisionless From these...
Chandra observations of large samples galaxy clusters detected in X-rays by ROSAT provide a new, robust determination the cluster mass functions at low and high redshifts. Statistical systematic errors are now sufficiently small, redshift leverage for function evolution to be used as useful growth structure-based dark energy probe. In this paper, we present cosmological parameter constraints obtained from 37 with 〈z〉 = 0.55 derived 400 deg2 serendipitous survey 49 brightest z ≈ 0.05 All-Sky...
We discuss the measurements of galaxy cluster mass functions at z ≈ 0.05 and 0.5 using high-quality Chandra observations samples derived from ROSAT PSPC All-Sky 400 deg2 surveys. provide a full reference for data analysis procedures, present updated calibration relations between total its X-ray indicators (TX, Mgas, YX) based on subsample low-z relaxed clusters, first measurement evolving LX–Mtot relation (with Mtot estimated obtained well defined statistically complete sample with...
We present detailed comparisons of the intracluster medium (ICM) in cosmological Eulerian cluster simulations with deep Chandra observations nearby relaxed clusters. To assess impact galaxy formation, we compare two sets simulations, one performed non-radiative regime and another radiative cooling several physical processes critical to various aspects formation: star metal enrichment stellar feedback. show that observed ICM properties outside cores are well-reproduced include while predict...
We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg$^2$ South Pole Telescope (SPT) data. This work represents the complete sample detected at high significance in 2500-square-degree SPT-SZ survey, which was completed 2011. A total 677 (409) cluster candidates are identified above signal-to-noise threshold $\xi$ =4.5 (5.0). Ground- and space-based optical near-infrared (NIR) imaging confirms overdensities similarly colored galaxies...
We present Chandra X-ray observations of the Hydra A cluster galaxies, and we report discovery structure in central 80 kpc cluster's X-ray-emitting gas. The most remarkable structures are depressions surface brightness, approximately 25-35 diameter, that coincident with A's radio lobes. nearly devoid gas, there is no evidence for shock-heated gas surrounding suggest within brightness was displaced as lobes expanded subsonically, leaving cavities hot atmosphere. temperature declines from 4...
The Chandra image of the merging, hot galaxy cluster 1E 0657-56 reveals a bow shock propagating in front bullet-like gas cloud just exiting disrupted core. This is first clear example cluster. From jumps density and temperature at shock, Mach number 2-3. corresponds to velocity 3000-4000 km s-1 relative main cluster, which means that traversed core 0.1-0.2 Gyr ago. 6-7 keV "bullet" appears be remnant dense cooling flow region once located center merging subcluster whose outer has been...
We present a systematic analysis of 43 nearby galaxy groups (kT500 = 0.7–2.7 keV or M500 1013–1014 h−1 M☉, 0.012 <z< 0.12), based on Chandra archival data. With robust background subtraction and modeling, we trace gas properties to at least r2500 for all groups. For 11 groups, can be robustly derived r500. an additional 12 derive r1000 estimate r500 from extrapolation. show that in spite the large variation temperature profiles inside 0.15 r500, these are similar > consistent with "universal...
X-ray observations of galaxy clusters potentially provide powerful cosmological probes if systematics due to our incomplete knowledge the ICM physics is understood and controlled. In this paper we present mock Chandra analyses cluster simulations assess measurements properties using a model procedure essentially identical that used in real data analysis. We show reconstruction three-dimensional density temperature profiles excellent for relaxed clusters, but still reasonably accurate...
We present comparison of X-ray proxies for the total cluster mass, including spectral temperature (Tx), gas mass measured within r500 (Mg), and new proxy, Yx, which is a simple product Tx Mg related to thermal energy ICM. use mock Chandra images constructed sample clusters simulated with eulerian N-body+gasdynamics adaptive mesh refinement ART code in concordance LCDM cosmology. The simulations achieve high spatial resolution include radiative cooling, star formation, other processes...
We present multiband photometry of 185 type-Ia supernovae (SNe Ia), with over 11,500 observations. These were acquired between 2001 and 2008 at the F. L. Whipple Observatory Harvard-Smithsonian Center for Astrophysics (CfA). This sample contains largest number homogeneously observed reduced nearby SNe Ia (z ≲ 0.08) published to date. It more than doubles sample, bringing SN cosmology point where systematic uncertainties dominate. Our natural system has a precision ≲0.02 mag in BVRIr'i' ≲0.04...
We present an analysis of ASCA spatially resolved spectroscopic data for a nearly complete sample bright clusters with redshifts between 0.04 and 0.09. Together several analyzed elsewhere using the same method, this consists 30 objects Te ≳ 3.5 keV which we obtained projected temperature profiles and, when possible, crude two-dimensional maps. The are A85, A119, A399, A401, A478, A644, A754, A780, A1650, A1651, A1795, A2029, A2065, A2142, A2256, A2319, A2597, A2657, A3112, A3266, A3376,...
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 design of a new polarization sensitive receiver, spt-3g, for 10-meter South Pole Telescope (spt). The spt-3g receiver will deliver factor ~20 improvement in mapping speed over current spt-pol. sensitivity enable advance from statistical detection B-mode anisotropy power to high signal-to-noise measurements individual modes, i.e., maps. This lead precise (~0.06 eV) constraints on sum neutrino masses with potential directly address mass hierarchy. It allow separation lensing...
We present Chandra gas temperature profiles at large radii for a sample of 13 nearby, relaxed galaxy clusters and groups, which includes A133, A262, A383, A478, A907, A1413, A1795, A1991, A2029, A2390, MKW4, RXJ1159+5531, USGC S152. The covers range average temperatures from 1 to 10 keV. are selected the archive or observed by us have sufficient exposures off-center area coverage enable accurate background subtraction reach accuracy better than 20-30% least r=0.4-0.5 r_180, three best...
We present UBVRI photometry of 44 Type Ia supernovae (SNe Ia) observed from 1997 to 2001 as part a continuing monitoring campaign at the Fred Lawrence Whipple Observatory Harvard-Smithsonian Center for Astrophysics. The data set comprises 2190 observations and is largest homogeneously reduced sample SNe date, nearly doubling number well-observed, nearby with published multicolor CCD light curves. large U-band unique addition, important connections high redshift. decline rate SN curves...
(abridged) We present cosmological constraints obtained from galaxy clusters identified by their Sunyaev-Zel'dovich effect signature in the 2500 square degree South Pole Telescope Sunyaev Zel'dovich survey. consider 377 cluster candidates at z>0.25 with a detection significance greater than five, corresponding to 95% purity threshold for compute on models using measured abundance as function of mass and redshift. include additional multi-wavelength observations, including Chandra X-ray data...
We present a catalog of galaxy cluster candidates, selected through their Sunyaev–Zel'dovich (SZ) effect signature in the first 720 deg2 South Pole Telescope (SPT) survey. This area was mapped with SPT 2008 and 2009 austral winters to depth ∼18 μKCMB-arcmin at 150 GHz; 550 it also ∼44 95 GHz. Based on optical imaging all 224 candidates near-infrared majority we have found and/or infrared counterparts for 158, which then classify as confirmed clusters. Of these 158 clusters, 135 were...
We use measurements from the South Pole Telescope (SPT) Sunyaev Zel'dovich (SZ) cluster survey in combination with X-ray to constrain cosmological parameters. present a statistical method that fits for scaling relations of SZ and observables mass while jointly fitting cosmology. The is generalizable multiple observables, self-consistently accounts effects selection uncertainties calibration on derived constraints. apply this data set consisting an SZ-selected catalog 18 galaxy clusters at z...
Lynx, one of the four strategic mission concepts under study for 2020 Astrophysics Decadal Survey, provides leaps in capability over previous and planned x-ray missions synergistic observations 2030s to a multitude space- ground-based observatories across all wavelengths. Lynx orders magnitude improvement sensitivity, on-axis subarcsecond imaging with arcsecond angular resolution large field view, high-resolution spectroscopy point-like extended sources 0.2- 10-keV range. The architecture...
We present a catalog of 203 clusters galaxies serendipitously detected in 647 ROSAT PSPC high Galactic latitude pointings covering 158 deg2. This is one the largest X-ray-selected cluster samples, comparable size only to All-Sky Survey sample nearby (Ebeling et al. 1997). detect inner 175 field view using spatial extent their X-ray emission. Fluxes range from 1.6 × 10-14 8 10-12 ergs s-1 cm-2 0.5-2 keV energy band. luminosities 1042 s-1, corresponding very poor groups, ~5 1044 rich clusters....