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Host Dark Matter Halos of Wide-field Infrared Survey Explorer-selected Obscured and Unobscured Quasars: Evidence for Evolution

Petter, Grayson C.; Hickox, Ryan C.; Alexander, David M.; Myers, Adam D.; Geach, James E.; Whalen, Kelly E.; Andonie, Carolina P.

Host Dark Matter Halos of Wide-field Infrared Survey Explorer-selected Obscured and Unobscured Quasars: Evidence for Evolution Thumbnail


Grayson C. Petter

Ryan C. Hickox

Adam D. Myers

James E. Geach

Kelly E. Whalen

Carolina P. Andonie


Obscuration in quasars may arise from steep viewing angles along the dusty torus, or instead may represent a distinct phase of supermassive black hole growth. We test these scenarios by probing the host dark matter halo environments of ∼1.4 million Wide-field Infrared Survey Explorer-selected obscured and unobscured quasars at 〈z〉 = 1.4 using angular clustering measurements as well as cross-correlation measurements of quasar positions with the gravitational lensing of the cosmic microwave background. We interpret these signals within a halo occupation distribution framework to conclude that obscured systems reside in more massive effective halos (∼1012.9 h−1 M⊙) than their unobscured counterparts (∼1012.6 h−1 M⊙), though we do not detect a difference in the satellite fraction. We find excellent agreement between the clustering and lensing analyses and show that this implies the observed difference is robust to uncertainties in the obscured quasar redshift distribution, highlighting the power of combining angular clustering and weak lensing measurements. This finding appears in tension with models that ascribe obscuration exclusively to orientation of the dusty torus along the line of sight, and instead may be consistent with the notion that some obscured quasars are attenuated by galaxy-scale or circumnuclear material during an evolutionary phase.

Journal Article Type Article
Acceptance Date Jan 29, 2023
Online Publication Date Mar 23, 2023
Publication Date Mar 20, 2023
Deposit Date Jun 20, 2023
Publicly Available Date Jun 20, 2023
Journal Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 946
Issue 1
Article Number 27
Public URL


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Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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