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Title: Predicting the Yields of z > 6.5 Quasar Surveys in the Era of Roman and Rubin
Abstract About 70 luminous quasars discovered atz> 6.5 are strongly biased toward the bright end, thus not providing a comprehensive view of quasar abundance beyond the cosmic dawn. We present the predicted results of the Roman/Rubin high-redshift quasar survey, yielding 3 times more, 2–4 mag deeper quasar samples, probing high-redshift quasars across a broad range of luminosities, especially faint quasars atLbol∼ 1010L⊙orM1450∼ −22, which are currently poorly explored. We include high-zquasars, galactic dwarfs, and low-zcompact galaxies with similar colors as quasar candidates. We create mock catalogs based on population models to evaluate selection completeness and efficiency. We utilize the classical color dropout method in thezandYbands to select primary quasar candidates, followed up with the Bayesian selection method to identify quasars. We show that overall selection completeness >80% and efficiency ∼10% at 6.5 <z< 9, with 180 quasars atz> 6.5, 20 atz> 7.5, and 2 atz> 8.5. The quasar yields depend sensitively on the assumed quasar luminosity shape and redshift evolution. Brown dwarf rejection through proper motion up to 50% can be made for stars brighter than 25 mag, low-zgalaxies dominate at fainter magnitude. Our results show that Roman/Rubin are able to discover a statistical sample of the earliest and faintest quasars in the Universe. The new valuable data sets are worth follow-up studies with JWST and Extremely Large Telescopes to determine the quasar luminosity function faint end slope and constraint the supermassive black holes growth in the early Universe.  more » « less
Award ID(s):
1908284
PAR ID:
10492511
Author(s) / Creator(s):
; ; ; ; ;
Publisher / Repository:
The Astrophysical Journal
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
956
Issue:
1
ISSN:
0004-637X
Page Range / eLocation ID:
52
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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