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Title: Revisiting the Lensed Fraction of High-redshift Quasars
Abstract

The observed lensed fraction of high-redshift quasars (∼0.2%) is significantly lower than previous theoretical predictions (≳4%). We revisit the lensed fraction of high-redshift quasars predicted by theoretical models, where we adopt recent measurements of galaxy velocity dispersion functions (VDFs) and explore a wide range of quasar luminosity function (QLF) parameters. We use both analytical methods and mock catalogs, which give consistent results. For ordinary QLF parameters and the depth of current high-redshift quasar surveys (mz≲ 22), our model suggests a multiply imaged fraction ofFmulti∼ 0.4%–0.8%. The predicted lensed fraction is ∼1%–6% for the brightestzs∼ 6 quasars (mz≲ 19), depending on the QLF. The systematic uncertainties of the predicted lensed fraction in previous models can be as large as 2–4 times and are dominated by the VDF. Applying VDFs from recent measurements decreases the predicted lensed fraction and relieves the tension between observations and theoretical models. Given the depth of current imaging surveys, there are ∼15 lensed quasars atzs> 5.5 detectable over the sky. Upcoming sky surveys like the Legacy Survey of Space and Time survey and the Euclid survey will find several tens of lensed quasars at this redshift range.

 
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Award ID(s):
1908284
NSF-PAR ID:
10362260
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
925
Issue:
2
ISSN:
0004-637X
Format(s):
Medium: X Size: Article No. 169
Size(s):
["Article No. 169"]
Sponsoring Org:
National Science Foundation
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