Michael D. Gladders
A5027341361- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astrophysical Phenomena and Observations
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- SAS software applications and methods
- Scientific Research and Discoveries
- Radio Astronomy Observations and Technology
- Astro and Planetary Science
- CCD and CMOS Imaging Sensors
- History and Developments in Astronomy
- Remote Sensing in Agriculture
- Pulsars and Gravitational Waves Research
- GNSS positioning and interference
- Impact of Light on Environment and Health
- Computational Physics and Python Applications
- Photocathodes and Microchannel Plates
- Calibration and Measurement Techniques
- Advanced Clustering Algorithms Research
- Dark Matter and Cosmic Phenomena
University of Chicago
2015-2024
Kavli Institute for Particle Astrophysics and Cosmology
2012-2024
University of Toronto
1998-2011
Carnegie Observatories
2002-2010
National Academies of Sciences, Engineering, and Medicine
2000-2008
Canada–France–Hawaii Telescope
2000-2008
University of Hawaii System
2000-2008
Cerro Tololo Inter-American Observatory
2002-2007
U.S. National Science Foundation
2002-2007
National Research Council Canada
2005
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...
The WiggleZ Dark Energy Survey is a survey of 240,000 emission line galaxies in the distant universe, measured with AAOmega spectrograph on 3.9-m Anglo-Australian Telescope (AAT). target are selected using ultraviolet photometry from GALEX satellite, flux limit NUV<22.8 mag. redshift range containing 90% 0.2<z<1.0. primary aim to precisely measure scale baryon acoustic oscillations (BAO) imprinted spatial distribution these at look-back times 4-8 Gyrs. Detailed forecasts indicate will BAO...
Numerous methods for finding clusters at moderate to high redshifts have been proposed in recent years, wavelengths ranging from radio X-rays. In this paper we describe a new method detecting two-band optical/near-IR imaging data. The relies upon the observation that all rich clusters, observed so far, appear red sequence of early-type galaxies. emerging picture is contain core population passively evolving elliptical galaxies are coeval and formed redshifts. search exploits strong empirical...
We report the discovery of eight new Milky Way companions in optical imaging data collected during first year Dark Energy Survey (DES). Each system is identified as a statistically significant over-density individual stars consistent with expected isochrone and luminosity function an old metal-poor stellar population. The objects span wide range absolute magnitudes (MV from to ), physical sizes (), heliocentric distances (). Based on low surface brightnesses, large sizes, and/or...
The Red-Sequence Cluster Survey (RCS) is a $\sim$100 square degree, two-filter imaging survey in the $R_C$ and $z'$ filters, designed primarily to locate characterise galaxy clusters redshifts as high $z=1.4$. This paper provides detailed description of strategy execution, including thorough discussion photometric astrometric calibration data. data are shown be calibrated typical uncertainty 0.03-0.05 magnitudes, with total uncertainties less than 0.25 arcseconds for most objects. We also...
We report the results of an 87 square-degree point-source survey centered at R.A. 5h30m, decl. -55 deg. taken with South Pole Telescope (SPT) 1.4 and 2.0 mm wavelengths arc-minute resolution milli-Jansky depth. Based on ratio flux in two bands, we separate detected sources into populations, one consistent synchrotron emission from active galactic nuclei (AGN) thermal dust. present source counts for each population 11 to 640 mJy 4.4 800 mm. The are dominated by synchrotron-dominated across...
Using the Atacama Large Millimeter/submillimeter Array, we have conducted a blind redshift survey in 3 mm atmospheric transmission window for 26 strongly lensed dusty star-forming galaxies (DSFGs) selected with South Pole Telescope. The sources were to S1.4 > 20 mJy and dust-like spectrum and, remove low-z sources, not bright radio (S843 MHz < 6 mJy) or far-infrared counterparts (S100 μm 1 Jy, S60 200 mJy). We robustly detect 44 line features our survey, which identify as redshifted emission...
(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 study the mass distribution of a sample 28 galaxy clusters using strong and weak lensing observations. The are selected via their properties as part Sloan Giant Arcs Survey (SGAS) from Digital Sky (SDSS). Mass modelling information giant arcs is combined with measurements deep Subaru/Suprime-cam images to primarily obtain robust constraints on concentration parameter shape distribution. find that cvir steep function mass, cvir∝M−0.59±0.12vir, value roughly consistent...
We present the results of a study weak lensing by galaxies based on 45.5 deg2 RC-band imaging data from Red-Sequence Cluster Survey (RCS). define sample lenses with 19.5 < RC 21 and background 21.5 24. first weak-lensing detection flattening galaxy dark matter halos. use simple model in which ellipticity halo is f times observed lens. find best-fit value = 0.77, suggests that halos are somewhat rounder than light distribution. The fact we detect significant implies well aligned Given average...
The South Pole Telescope (SPT) is currently surveying 2500 deg^2 of the southern sky to detect massive galaxy clusters out epoch their formation using Sunyaev-Zel'dovich (SZ) effect. This paper presents a catalog 26 most significant SZ cluster detections in full survey region. includes 14 which have been previously identified and 12 that are new discoveries. These were fields observed two differing noise depths: 1500 at final SPT depth 18 uK-arcmin 150 GHz, 1000 54 uK-arcmin. Clusters...
Abstract We present a cosmic shear analysis of the 100-deg2 weak-lensing survey, combining data from CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ∼100 deg2, with median source redshift z∼ 0.78, this combined survey allows us to place tight joint constraints on matter density parameter Ωm, amplitude power spectrum σ8, finding σ8(Ωm/0.24)0.59= 0.84 ± 0.05. Tables measured correlation function calculated covariance matrix for each are included as supplementary material online...
We present first results on the cooling properties derived from Chandra X-ray observations of 83 high-redshift (0.3 < z 1.2) massive galaxy clusters selected by their Sunyaev–Zel'dovich signature in South Pole Telescope data. measure each cluster's central time, entropy, and mass deposition rate, compare these to those for local cluster samples. find no significant evolution ∼ 0 1 distribution properties, suggesting that cores is stable over long periods time. also average cool core entropy...
The Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) is a z'-passband imaging survey, consisting deep (z' ~ 24 AB) observations made from both hemispheres using CFHT 3.6m and CTIO 4m telescopes. survey was designed with primary aim detecting galaxy clusters at z >~ 1. In tandem pre-existing 3.6um Space Telescope SWIRE Legacy Survey, SpARCS detects an infrared adaptation two-filter red-sequence cluster technique. total effective area 41.9 deg^2. this paper, we provide overview...
We present strong-lensing models, as well mass and magnification maps, for the cores of six HST Frontier Fields galaxy clusters. Our parametric lens models are constrained by locations redshifts multiple image systems lensed background galaxies. use a combination photometric spectroscopic sources obtained us (for Abell 2744 S1063), collected from literature, or kindly provided lensing community. Using our results, we (1) compare derived distribution each cluster to its light distribution,...
We derive cosmological constraints using a galaxy cluster sample selected from the 2500~deg$^2$ SPT-SZ survey. The spans redshift range $0.25< z<1.75$ and contains 343 clusters with SZ detection significance $\xi>5$. is supplemented optical weak gravitational lensing measurements of 32 $0.29<z<1.13$ (from Magellan HST) X-ray 89 $0.25<z<1.75$ Chandra). rely on minimal modeling assumptions: i) provides an accurate means measuring halo masses, ii) mean observables are related to true mass...
The second Red-sequence Cluster Survey (RCS-2) is a ~1000 square degree, multi-color imaging survey using the square-degree imager, MegaCam, on Canada-France-Hawaii Telescope (CFHT). It designed to detect clusters of galaxies over redshift range 0.1<~z<~1. primary aim build statistically complete, large (~10^4) sample clusters, covering sufficiently long baseline be able place constraints cosmological parameters via evolution cluster mass function. Other main science goals include building...
We infer the properties of massive star populations using far-ultraviolet stellar continua 61 star-forming galaxies: 42 at low-z observed with HST and 19 z~2 from Megasaura sample. fit each continuum a linear combination up to 50 single age metallicity Starburst99 models. From these fits, we derive light-weighted ages metallicities, which agree wind photospheric spectral features, shapes strengths ionizing continua. Inferred metallicities span 0.05-1.5 Z$_\odot$ are similar measured nebular...
The IMACS Cluster Building Survey (ICBS) provides spectra of ~2200 galaxies 0.31<z<0.54 in 5 rich clusters (R <= Mpc) and the field. Infalling, dynamically cold groups with tens members account for approximately half supercluster population, contributing to a growth cluster mass ~100% by today. ICBS distinguish non-starforming (PAS) poststarburst (PSB) from starforming -- continuously (CSF) or starbursts, (SBH SBO), identified anomalously strong H-delta absorption [O II] emission. For...
We present optical and near-IR imaging spectroscopy of SGAS J105039.6$+$001730, a strongly lensed galaxy at z $=$ 3.6252 magnified by $>$30$\times$, derive its physical properties. measure stellar mass log(M$_{*}$/M$_{\odot}$) 9.5 $\pm$ 0.35, star formation rates from [O II]$\lambda$$\lambda$3727 H-$\beta$ 55 20 84 17 M$_{\odot}$ yr$^{-1}$, respectively, an electron density n$_{e} \leq$ 10$^{3}$ cm$^{-2}$, temperature T$_{e} 14000 K, metallicity 12+log(O/H) 8.3 0.1. The strong C...
Abstract Extreme, young stellar populations are considered to be the primary contributor cosmic reionization. How Lyman continuum (LyC) escapes these galaxies remains highly elusive, and it is challenging observe this process in actual LyC emitters without resolving relevant physical scales. We investigate Sunburst Arc, a strongly lensed emitter at z = 2.37 that reveals an exceptionally small-scale (tens of parsecs) region high escape. The small (<100 pc) LyC-leaking has extreme...