@article{5850371f8dc54ada996bba7c5fe7a48d,
title = "Characterizing the chemically enriched circumgalactic medium of ~38 000 luminous red galaxies in SDSS DR12",
abstract = "We report a definitive detection of chemically enriched cool gas around massive quiescent galaxies at z ≈ 0.4-0.7. The result is based on a survey of 37 621 luminous red galaxy (LRG)- quasi-stellar object pairs in SDSS DR12 with projected distance d < 500 kpc. The LRGs are characterized by a predominantly old stellar population (age ≳ 1 Gyr) with 13 per cent displaying [O II] emission features and LINER-like spectra. Both passive and [O II]-emitting LRGs share the same stellar mass distribution with a mean of 〈log (M*/M⊙)〉 ≈ 11.4 and a dispersion of 0.2 dex. Both LRG populations exhibit associated strong MgII absorbers out to d < 500 kpc. The mean gas covering fraction at d ≲ 120 kpc is 〈κ〉MgII > 15 per cent and declines quickly to 〈κ〉MgII ≈ 5 per cent at d ≲ 500 kpc. No clear dependence on stellar mass is detected for the observed Mg II absorption properties. The observed velocity dispersion of MgII-absorbing gas relative to either passive or [O II]-emitting LRGs is merely 60 per cent of what is expected from virial motion in these massive haloes. While no apparent azimuthal dependence is seen for 〈κ〉MgII around passive LRGs at all radii, a modest enhancement in 〈κ〉MgII is detected along the major axis of [O II]-emitting LRGs at d < 50 kpc. The suppressed velocity dispersion of MgII-absorbing gas around both passive and [O II]-emitting LRGs, together with an elevated 〈κ〉MgII along the major axis of [O II]-emitting LRGs at d < 50 kpc, provides important insights into the origin of the observed chemically enriched cool gas in LRG haloes. We consider different scenarios and conclude that the observed Mg II absorbers around LRGs are best explained by a combination of cool clouds formed in thermally unstable LRG haloes and satellite accretion through filaments.",
keywords = "CD, Galaxies: elliptical and lenticular, Galaxies: haloes, Galaxies: statistics, Quasars: absorption lines, Surveys",
author = "Huang, {Yun Hsin} and Chen, {Hsiao Wen} and Johnson, {Sean D.} and Weiner, {Benjamin J.}",
note = "Funding Information: It is a pleasure to thank Jenny Greene, Hung-Jin Huang, Cameron Liang, Michael Rauch and Mark Voit for helpful discussions on the interpretations of our main findings. We thank an anonymous referee for constructive comments that helped improve the presentation of the paper. HWC acknowledges the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1066293, and the organizers of the workshop on the Physics of Accretion and Feedback in the Circumgalactic Medium for a productive visit in 2015 June, during which components of the work presented were accomplished. We are grateful to the SDSS collaboration for producing and maintaining the SDSS public data archive. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the participating institutions, the National Science Foundation and the US Department of Energy Office of Science. The SDSS-III website is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the participating institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington and Yale University. Publisher Copyright: {\textcopyright} 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.",
year = "2016",
month = jan,
day = "11",
doi = "10.1093/mnras/stv2327",
language = "English (US)",
volume = "455",
pages = "1713--1727",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "2",
}