The COSMOS Survey:
                    <i>Hubble Space Telescope</i>
                    Advanced Camera for Surveys Observations and Data Processing

Koekemoer, Anton M.; Aussel, H.; Calzetti, D.; Capak, P.; Giavalisco, Mauro; Kneib, Jean-Paul; Leauthaud, Alexie; Fèvre, O. Le; McCracken, H. J.; Massey, Richard; Mobasher, Bahram; Rhodes, Jason; Scoville, N. Z.; Shopbell, P. L.

doi:10.1086/520086

Cited by 640 publications

(665 citation statements)

References 15 publications

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“…Indeed the simulated catalogs agree, by construction, with the size distribution measured in the COSMOS ACS imaging survey (Koekemoer et al 2007), (Leauthaud et al 2007). No other survey capable of resolving faint galaxies approaches the size of the COSMOS/ACS data.…”

Section: Galaxy-sizessupporting

confidence: 56%

Designing future dark energy space missions

Jouvel¹,

Kneib²,

Ilbert

et al. 2009

A&A

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Context. Future dark energy space missions such as JDEM and EUCLID are being designed to survey the galaxy population to trace the geometry of the universe and the growth of structure, which both depend on the cosmological model. To reach the goal of high precision cosmology they need to evaluate the capabilities of different instrument designs based on realistic mock catalogs of the galaxy distribution. Aims. The aim of this paper is to construct realistic and flexible mock catalogs based on our knowledge of galaxy populations from current deep surveys. We explore two categories of mock catalogs: (i) based on luminosity functions that we fit to observations (GOODS, UDF, COSMOS, VVDS); (ii) based on the observed COSMOS galaxy distribution. Methods. The COSMOS mock catalog benefits from all the properties of the data-rich COSMOS survey and the highly accurate photometric redshift distribution based on 30-band photometry. Nevertheless this catalog is limited by the depth of the COSMOS survey. Thus, we also evaluate a mock galaxy catalog generated from luminosity functions using the Le Phare software. For these two catalogs, we have produced simulated number counts in several bands, color diagrams and redshift distributions for validation against real observational data. Results. Using these mock catalogs we derive some basic requirements to help design future Dark Energy missions in terms of the number of galaxies available for the weak-lensing analysis as a function of the PSF size and depth of the survey. We also compute the spectroscopic success rate for future spectroscopic redshift surveys (i) aiming at measuring BAO in the case of the wide field spectroscopic redshift survey, and (ii) for the photometric redshift calibration survey which is required to achieve weak lensing tomography with great accuracy. In particular, we demonstrate that for the photometric redshift calibration, using only NIR (1-1.7 μm) spectroscopy, we cannot achieve a complete spectroscopic survey down to the limit of the photometric survey (I < 25.5). Extending the wavelength coverage of the spectroscopic survey to cover 0.6-1.7 μm will then improve the fraction of very secure spectroscopic redshifts to nearly 80% of the galaxies, making possible a very accurate photometric redshift calibration. Conclusions. We have produced two realistic mock galaxy catalogs that can be used in determining the best survey strategy for future dark-energy missions in terms of photometric redshift accuracy and spectroscopic redshift surveys yield. These catalogues are publicly accessible at http://lamwws.oamp.fr/cosmowiki/RealisticSpectroPhotCat, or at the CDS.

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Section: Galaxy-sizessupporting

confidence: 56%

Designing future dark energy space missions

Jouvel¹,

Kneib²,

Ilbert

et al. 2009

A&A

Self Cite

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“…On the contrary, galaxies will not be flagged due to their shallower light profiles, leading to different effective stacked PSFs for stars and galaxies. To avoid any influence on the lensing analysis, we create separate stacks for the shape measurement of galaxies and stars, where we use close to default cosmic ray rejection parameters for the former (driz_cr_snr="4.0 3.0", driz_cr_scale="1.2 0.7", see Koekemoer et al 2002Koekemoer et al , 2007, but less aggressive masking for the latter (driz_cr_snr="5.0 3.0", driz_cr_scale="3.0 0.7"). As a result, the false masking of stars is substantially reduced.…”

Section: Hst/acs Datamentioning

confidence: 99%

Evidence of the accelerated expansion of the Universe from weak lensing tomography with COSMOS

Schrabback

Hartlap

Joachimi

et al. 2010

A&A

340

454

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We present a comprehensive analysis of weak gravitational lensing by large-scale structure in the Hubble Space Telescope Cosmic Evolution Survey (COSMOS), in which we combine space-based galaxy shape measurements with ground-based photometric redshifts to study the redshift dependence of the lensing signal and constrain cosmological parameters. After applying our weak lensingoptimized data reduction, principal-component interpolation for the spatially, and temporally varying ACS point-spread function, and improved modelling of charge-transfer inefficiency, we measured a lensing signal that is consistent with pure gravitational modes and no significant shape systematics. We carefully estimated the statistical uncertainty from simulated COSMOS-like fields obtained from ray-tracing through the Millennium Simulation, including the full non-Gaussian sampling variance. We tested our lensing pipeline on simulated space-based data, recalibrated non-linear power spectrum corrections using the ray-tracing analysis, employed photometric redshift information to reduce potential contamination by intrinsic galaxy alignments, and marginalized over systematic uncertainties. We find that the weak lensing signal scales with redshift as expected from general relativity for a concordance ΛCDM cosmology, including the full cross-correlations between different redshift bins. Assuming a flat ΛCDM cosmology, we measure σ 8 (Ω m /0.3) 0.51 = 0.75 ± 0.08 from lensing, in perfect agreement with WMAP-5, yielding joint constraints Ω m = 0.266 +0.025 −0.023 , σ 8 = 0.802 +0.028 −0.029 (all 68.3% conf.). Dropping the assumption of flatness and using priors from the HST Key Project and Big-Bang nucleosynthesis only, we find a negative deceleration parameter q 0 at 94.3% confidence from the tomographic lensing analysis, providing independent evidence of the accelerated expansion of the Universe. For a flat wCDM cosmology and prior w ∈ [−2, 0], we obtain w < −0.41 (90% conf.). Our dark energy constraints are still relatively weak solely due to the limited area of COSMOS. However, they provide an important demonstration of the usefulness of tomographic weak lensing measurements from space.

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“…sen from Hubble Space Telescope (HST ) F 814W imaging (Koekemoer et al 2007) with 15 < IAB < 22.5 across the 1.7 deg 2 COSMOS field. The target selection is based on a combination of nearly random selection and compulsory targets.…”

Section: Zcosmosmentioning

confidence: 99%

The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

Schulze

Bongiorno

Gavignaud

et al. 2015

Monthly Notices of the Royal Astronomical Society

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159

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We present a census of the active black hole population at 1 < z < 2, by constructing the bivariate distribution function of black hole mass and Eddington ratio, employing a maximum likelihood fitting technique. The study of the active black hole mass function (BHMF) and the Eddington ratio distribution function (ERDF) allows us to clearly disentangle the active galactic nuclei (AGN) downsizing phenomenon, present in the AGN luminosity function, into its physical processes of black hole mass downsizing and accretion rate evolution. We are utilizing type-1 AGN samples from three optical surveys (VVDS, zCOSMOS and SDSS), that cover a wide range of 3 dex in luminosity over our redshift interval of interest. We investigate the cosmic evolution of the AGN population as a function of AGN luminosity, black hole mass and accretion rate. Compared to z = 0, we find a distinct change in the shape of the BHMF and the ERDF, consistent with downsizing in black hole mass. The active fraction or duty cycle of type-1 AGN at z ∼ 1.5 is almost flat as a function of black hole mass, while it shows a strong decrease with increasing mass at z = 0. We are witnessing a phase of intense black hole growth, which is largely driven by the onset of AGN activity in massive black holes towards z = 2. We finally compare our results to numerical simulations and semi-empirical models and while we find reasonable agreement over certain parameter ranges, we highlight the need to refine these models in order to match our observations.

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The COSMOS Survey: Hubble Space Telescope Advanced Camera for Surveys Observations and Data Processing

Cited by 640 publications

References 15 publications

Designing future dark energy space missions

Designing future dark energy space missions

Evidence of the accelerated expansion of the Universe from weak lensing tomography with COSMOS

The cosmic growth of the active black hole population at 1 <z <2 in zCOSMOS, VVDS and SDSS

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