Journal article

Unresolved z similar to 8 Point Sources and Their Impact on the Bright End of the Galaxy Luminosity Function

Yuzo Ishikawa, Takahiro Morishita, Massimo Stiavelli, Nicha Leethochawalit, Harry Ferguson, Roberto Gilli, Charlotte Mason, Michele Trenti, Tommaso Treu, Colin Norman

ASTROPHYSICAL JOURNAL | IOP Publishing Ltd | Published : 2022

Abstract

The distribution and properties of the first galaxies and quasars are critical pieces of the puzzle in understanding galaxy evolution and cosmic reionization. Previous studies have often excluded unresolved sources as potential low-redshift interlopers. We combine broadband color and photometric redshift analysis with morphological selections to identify a robust sample of candidates consistent with unresolved point sources at redshifts z ∼ 8 using deep Hubble Space Telescope images. We also examine G141 grism spectroscopic data to identify and eliminate dwarf star contaminants. From these analyses, we identify three bright (MUV  −22 AB mag) dropout point sources at 7.5 < z < 8.1. Spectral ..

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University of Melbourne Researchers

Grants

Awarded by NASA from the Space Telescope Science Institute


Awarded by NASA


Awarded by Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)


Awarded by VILLUM FONDEN


Awarded by Danish National Research Foundation


Awarded by 3D-HST Treasury Program


Funding Acknowledgements

Support for this work was provided by NASA through grant Nos. HST-GO-15212.002 and HST-AR-15804.002-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. This work is based on observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA HST, which is operated by AURA, Inc., under NASA contract NAS5-26555. This work is based on observations taken by the CANDELS Multi-cycle Treasury Program with the NASA/ESA HST, which is operated by AURA, Inc., under NASA contract NAS5-26555. This research has benefited from the SpeX Prism Library (and the SpeX Prism Library Analysis Toolkit), maintained by Adam Burgasser at http://www.browndwarfs.org/spexprism.The authors would like to thank the anonymous referee for the helpful suggestions for improving the paper. N.L. acknowledges that parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project No. CE170100013. C.M. acknowledges support from VILLUM FONDEN under grant 37459, and from the Danish National Research Foundation through grant DNRF140. Y.I. also thanks Nadia Zakamska for helpful discussions.