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Title: Probing the z > 6 universe with the first Hubble frontier fields cluster A2744

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z ≳ 6) galaxies. We report the detection of 15 I {sub 814} dropout candidates at z ∼ 6-7 and one Y {sub 105} dropout at z ∼ 8 in a total survey area of 1.43 arcmin{sup 2} in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ∼ 6 and z ∼ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ∼ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on amore » shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M {sub UV} ∼–18.5, corresponding to 0.2L {sup *} at z ∼ 7 with one identified object at M {sub UV} ∼–15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields.« less
Authors:
;  [1] ;  [2] ; ;  [3] ;  [4] ;  [5] ; ;  [6] ;  [7] ;  [8]
  1. Laboratoire d'Astrophysique, Ecole Polytechnique Fédérale de Lausanne, Observatoire de Sauverny, CH-1290 Versoix (Switzerland)
  2. CRAL, Observatoire de Lyon, Université Lyon 1, 9 Avenue Ch. André, 69561 Saint Genis Laval Cedex (France)
  3. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ, 85721 (United States)
  4. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, Hawaii 96822 (United States)
  5. Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban, 4041 South Africa (South Africa)
  6. Aix Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille (France)
  7. Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain)
  8. Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States)
Publication Date:
OSTI Identifier:
22356993
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DETECTION; FORECASTING; GALAXIES; GALAXY CLUSTERS; GRAVITATIONAL LENSES; LIMITING VALUES; LUMINOSITY; MASS DISTRIBUTION; RED SHIFT; SPACE; TELESCOPES; ULTRAVIOLET RADIATION; UNIVERSE