Anton M. Koekemoer
A5043083140- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Astrophysics and Cosmic Phenomena
- CCD and CMOS Imaging Sensors
- Radio Astronomy Observations and Technology
- Cosmology and Gravitation Theories
- Calibration and Measurement Techniques
- Scientific Research and Discoveries
- Geophysics and Gravity Measurements
- Remote Sensing in Agriculture
- Advanced Vision and Imaging
- Solar and Space Plasma Dynamics
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- History and Developments in Astronomy
- Photocathodes and Microchannel Plates
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Plant Water Relations and Carbon Dynamics
Space Telescope Science Institute
2016-2025
Colby College
2013-2024
Centre National de la Recherche Scientifique
2024
Aix-Marseille Université
2024
Rochester Institute of Technology
2024
Michigan Science Center
2001-2023
Universities Space Research Association
2023
Johns Hopkins University
2023
Arizona State University
2023
Max Planck Institute for Astronomy
2013-2019
The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) is designed to document the first third of galactic evolution, over approximate redshift (z) range 8--1.5. It will image >250,000 distant galaxies using three separate cameras on Hubble Space Telescope, from mid-ultraviolet near-infrared, and find measure Type Ia supernovae at z>1.5 test their accuracy as standardizable candles for cosmology. Five premier multi-wavelength sky regions are selected, each with...
We explore the inter-relationships between mass, star-formation rate and environment in SDSS, zCOSMOS other surveys. The differential effects of mass are completely separable to z ~ 1, indicating that two distinct processes operating, "mass-quenching" "environment-quenching". Environment-quenching, at fixed over-density, evidently does not change with epoch suggesting it occurs as large-scale structure develops Universe. observed constancy mass-function shape for star-forming galaxies,...
This special issue of the Astrophysical Journal Letters is dedicated to presenting initial results from Great Observatories Origins Deep Survey (GOODS) that are primarily, but not exclusively, based on multiband imaging data obtained with Hubble Space Telescope and Advanced Camera for Surveys (ACS). The survey covers roughly 320 arcmin2 in ACS F435W, F606W, F814W, F850LP bands, divided into two well-studied fields. Existing deep observations Chandra X-Ray Observatory ground-based facilities...
This paper describes the Hubble Space Telescope imaging data products and reduction procedures for Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). survey is designed to document evolution of galaxies black holes at $z\sim1.5-8$, study Type Ia SNe beyond $z>1.5$. Five premier multi-wavelength sky regions are selected, each with extensive multiwavelength observations. The primary CANDELS consist obtained in Wide Field Camera 3 / infrared channel (WFC3/IR) UVIS channel,...
Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3π$ Steradian Survey and Medium Deep in 5 bands ($grizy_{P1}$). The mean 5$σ$ point source limiting sensitivities stacked 3$π$ $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. upper bound on systematic uncertainty photometric calibration across is 7-12 millimag depending bandpass. astrometric using Gaia frame comes from comparison results with Gaia: standard deviation median residuals ($...
We present the deepest 100 to 500 μm far-infrared observations obtained with Herschel Space Observatory as part of GOODS-Herschel key program, and examine infrared (IR) 3–500 spectral energy distributions (SEDs) galaxies at 0 < z 2.5, supplemented by a local reference sample from IRAS, ISO, Spitzer, AKARI data. determine projected star formation densities their radio mid-IR continuum sizes.
ABSTRACT We present the COSMOS2015 24 catalog, which contains precise photometric redshifts and stellar masses for more than half a million objects over 2deg 2 COSMOS field. Including new <?CDATA ${{YJHK}}_{{\rm{s}}}$?> images from UltraVISTA-DR2 survey, Y-band Subaru/Hyper-Suprime-Cam, infrared data Spitzer Large Area Survey with Hyper-Suprime-Cam legacy program, this near-infrared-selected catalog is highly optimized study of galaxy evolution environments in early universe. To maximize...
zCOSMOS is a large-redshift survey that being undertaken in the COSMOS field using 600 hr of observation with VIMOS spectrograph on 8 m VLT. The designed to characterize environments galaxies from 100 kpc scales galaxy groups up Mpc scale cosmic web and produce diagnostic information active galactic nuclei. consists two parts: (1) zCOSMOS-bright, magnitude-limited I-band IAB < 22.5 sample about 20,000 0.1 z 1.2 covering whole 1.7 deg2 ACS field, for which parameters at ~ 0.7 are be directly...
This paper presents the Hubble Ultra Deep Field (HUDF), a 1 million s exposure of an 11 arcmin2 region in southern sky with Advanced Camera for Surveys on Space Telescope using Director's Discretionary Time. The time was divided among four filters, F435W (B435), F606W (V606), F775W (i775), and F850LP (z850), to give approximately uniform limiting magnitudes mAB ∼ 29 point sources. image contains at least 10,000 objects, presented here as catalog, vast majority which are galaxies. Visual...
The Cluster Lensing And Supernova survey with Hubble (CLASH) is a 524-orbit multi-cycle treasury program to use the gravitational lensing properties of 25 galaxy clusters accurately constrain their mass distributions. survey, described in detail this paper, will definitively establish degree concentration dark matter cluster cores, key prediction CDM. CLASH sample larger and less biased than current samples space-based imaging studies similar depth, as we have minimized lensing-based...
We present imaging data and photometry for the COSMOS survey in 15 photometric bands between 0.3 2.4 μm. These include taken on Subaru 8.3 m telescope, KPNO CTIO 4 telescopes, CFHT 3.6 telescope. Special techniques are used to ensure that relative calibration is better than 1% across field of view. The absolute accuracy from standard-star measurements found be 6%. corrected using galaxy spectra, providing colors accurate 2% or better. Stellar counts agree well with expected values. Finally,...
Spectroscopic+photometric redshifts, stellar mass estimates, and rest-frame colors from the 3D-HST survey are combined with structural parameter measurements CANDELS imaging to determine galaxy size–mass distribution over redshift range 0 < z 3. Separating early- late-type galaxies on basis of star-formation activity, we confirm that early-type average smaller than at all find a significantly different rate size evolution fixed mass, fast for population, Reff∝(1 + z)−1.48, moderate z)−0.75....
We analyze the dependence of galaxy structure (size and Sersic index) mode star formation (\Sigma_SFR SFR_IR/SFR_UV) on position galaxies in SFR versus Mass diagram. Our sample comprises roughly 640000 at z~0.1, 130000 z~1, 36000 z~2. Structural measurements for all but z~0.1 were based HST imaging, SFRs are derived using a Herschel-calibrated ladder indicators. find that correlation between stellar population (i.e., 'Hubble sequence') is already place since least z~2.5. At epochs, typical...
We follow the galaxy stellar mass assembly by morphological and spectral type in COSMOS 2 deg2 field. derive functions densities from z = to 0.2 using 196,000 galaxies selected at F3.6 μm > 1 μJy with accurate photometric redshifts ( i+ < 22.5). Using a classification, we find that ∼ is an epoch of transition quiescent galaxies. Their density increases 1.1 dex between 1.5–2 0.8–1 (Δt 2.5 Gyr), but only 0.3 0.1 6 Gyr). Then, add information 80%–90% massive have elliptical morphology 0.8....
We present a robust measurement and analysis of the rest-frame ultraviolet (UV) luminosity function at z=4-8. use deep Hubble Space Telescope imaging over CANDELS/GOODS fields, Ultra Deep Field Year 1 Frontier parallel observations. These surveys provides an effective volume 0.6-1.2 x 10^6 Mpc^3 this epoch, allowing us to perform search for faint (M_UV=-18) bright (M_UV < -21) galaxies. select candidate galaxies using well-tested photometric redshift technique with careful screening...
We report on a complete sample of seven luminous early-type galaxies in the Hubble Ultra Deep Field (UDF) with spectroscopic redshifts between 1.39 and 2.47, to KAB < 23. Using BzK selection criterion, we have preselected set objects over UDF, which fulfill photometric conditions for being passively evolving at z > 1.4. Low-resolution spectra these been extracted from Space Telescope (HST) ACS grism data taken UDF by Grism Program Extragalactic Science (GRAPES) project. Redshifts identified...
We describe the details of Hubble Space Telescope (HST) Advanced Camera for Surveys / Wide Field Channel (ACS/WFC) observations COSMOS field, including data calibration and processing procedures. obtained a total 583 orbits HST ACS/WFC imaging in F814W filter, covering field that is 1.64 square degrees area, largest contiguous ever imaged with HST. The median exposure depth across 2028 seconds (one orbit), achieving limiting point-source AB(F814W) = 27.2 (5 sigma). also present about...
We explore the redshift evolution of specific star formation rate (SSFR) for galaxies different stellar mass by drawing on a deep 3.6 μm selected sample >105 in 2 deg2 COSMOS field. The average (SFR) subsets these is estimated with stacked 1.4 GHz radio continuum emission. separately consider total and subset that shows evidence substantive recent rest-frame optical spectral energy distributions. At redshifts 0.2 < z 3 both populations show strong mass-independent decrease their SSFR toward...
In this paper we present the source catalog obtained from a 942 ks exposure of Chandra Deep Field South (CDFS), using Advanced CCD Imaging Spectrometer (ACIS-I) on X-ray Observatory. Eleven individual pointings made between 1999 October and 2000 December were combined to generate final image used for object detection. Catalog generation proceeded simultaneously two different methods; method our own design modified version SExtractor algorithm, wavelet transform technique developed...
The Spitzer-COSMOS survey (S-COSMOS) is a Legacy program (Cycles 2+3) designed to carry out uniform deep of the full 2 sq deg COSMOS field in all seven Spitzer bands (3.6, 4.5, 5.6, 8.0, 24.0, 70.0, 160.0 u). This paper describes parameters, mapping strategy, data reduction procedures, achieved sensitivities date, and complete set for future reference. We show that observed infrared backgrounds S-COSMOS are within 10% predicted background levels. fluctuations at 24u have been measured do not...
We present spectroscopic redshifts of a large sample galaxies with IAB < 22.5 in the COSMOS field, measured from spectra 10,644 objects that have been obtained first two years observations zCOSMOS-bright redshift survey. These include statistically complete subset 10,109 objects. The average accuracy individual is 110 km s−1, independent redshift. reliability described by Confidence Class has empirically calibrated through repeat over 600 galaxies. There very good agreement between and...
Spitzer IRAC selection is a powerful tool for identifying luminous AGN. For deep data, however, the AGN wedges currently in use are heavily contaminated by star-forming galaxies, especially at high redshift. Using large samples of and high-redshift galaxies COSMOS, we redefine criteria surveys. The new designed to be both highly complete reliable, incorporate best aspects current infrared power-law while excluding redshift selected via BzK, DRG, LBG, SMG criteria. At QSO-luminosities log...
[abridged] We present point-source catalogs for the 4Ms Chandra Deep Field-South (CDF-S), which is deepest survey to date and covers an area of 464.5 arcmin^2. provide a main source catalog, contains 740 X-ray point sources that are detected with wavdetect at false-positive probability threshold 1E-5 also satisfy binomial-probability source-selection criterion P<0.004; this approach designed maximize number reliable detected. A total 300 main-catalog new compared previous 2Ms CDF-S sources....
In this the first of a series Letters, we present panchromatic data set in Extended Groth Strip region sky. Our survey, All-Wavelength International Survey (AEGIS), aims to study physical properties and evolutionary processes galaxies at z ~ 1. It includes following deep, wide-field imaging sets: Chandra/ACIS X-ray, GALEX ultraviolet, CFHT/MegaCam Legacy optical, CFHT/CFH12K Hubble Space Telescope/ACS optical NICMOS near-infrared, Palomar/WIRC Spitzer/IRAC mid-infrared, Spitzer/MIPS...