Bouwens, RJ, Stefanon, M, Oesch, PA, Illingworth, GD, Nanayakkara, T, Roberts-Borsani, G, Labbe, I and Smit, R (2019) Newly Discovered Bright z similar to 9-10 Galaxies and Improved Constraints on Their Prevalence Using the Full CANDELS Area. Astrophysical Journal, 880 (1). ISSN 0004-637X

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Abstract

We report the results of an expanded search for z ~ 9–10 candidates over the ~883 arcmin2 CANDELS+ERS fields. This study adds 147 arcmin2 to the search area we consider over the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) COSMOS, UDS, and EGS fields, while expanding our selection to include sources with bluer J 125 − H 160 colors than our previous J 125 − H 160 > 0.5 mag selection. In searching for new z ~ 9–10 candidates, we make full use of all available Hubble Space Telescope (HST), Spitzer/IRAC, and ground-based imaging data. As a result of our expanded search and use of broader color criteria, three new candidate z ~ 9–10 galaxies are identified. We also find again the z = 8.683 source previously confirmed by Zitrin et al. This brings our sample of probable z ~ 9–11 galaxy candidates over the CANDELS+ERS fields to 19 sources in total, equivalent to one candidate per 47 arcmin2 (one per 10 WFC3/IR fields). To be comprehensive, we also discuss 28 mostly lower likelihood z ~ 9–10 candidates, including some sources that seem to be reliably at z > 8 using the HST+IRAC data alone, but which the ground-based data show are much more likely at z < 4. One case example is a bright z ~ 9.4 candidate, COS910-8, which seems instead to be at z ~ 2. Based on this expanded sample, we obtain a more robust luminosity function (LF) at z ~ 9 and improved constraints on the volume density of bright z ~ 9 and z ~ 10 galaxies. Our improved z ~ 9–10 results again reinforce previous findings for strong evolution in the UV LF at z > 8, with a factor of ~10 evolution seen in the luminosity density from z ~ 10 to z ~ 8.

Item Type:	Article
Uncontrolled Keywords:	Science & Technology; Physical Sciences; Astronomy & Astrophysics; galaxies: evolution; galaxies: formation; galaxies: high-redshift; LYMAN-BREAK GALAXIES; ULTRA-DEEP FIELD; ULTRAVIOLET LUMINOSITY DENSITY; HUBBLE FRONTIER FIELDS; REDSHIFT; EVOLUTION; REIONIZATION; COSMOS; POPULATION; CAMERA; Science & Technology; Physical Sciences; Astronomy & Astrophysics; galaxies: evolution; galaxies: formation; galaxies: high-redshift; LYMAN-BREAK GALAXIES; ULTRA-DEEP FIELD; ULTRAVIOLET LUMINOSITY DENSITY; HUBBLE FRONTIER FIELDS; REDSHIFT; EVOLUTION; REIONIZATION; COSMOS; POPULATION; CAMERA; 0201 Astronomical and Space Sciences; 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics; 0306 Physical Chemistry (incl. Structural); Astronomy & Astrophysics
Subjects:	Q Science > QB Astronomy Q Science > QC Physics
Divisions:	Astrophysics Research Institute
Publisher:	American Astronomical Society; IOP Publishing
SWORD Depositor:	A Symplectic
Date Deposited:	15 Nov 2022 12:23
Last Modified:	15 Nov 2022 12:30
DOI or ID number:	10.3847/1538-4357/ab24c5
URI:	https://researchonline.ljmu.ac.uk/id/eprint/18133

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