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Title: Quasars Probing Galaxies. I. Signatures of Gas Accretion at Redshift z ≈ 0.2

Abstract

We describe the kinematics of circumgalactic gas near the galactic plane, combining new measurements of galaxy rotation curves and spectroscopy of background quasars. The sightlines pass within 19–93 kpc of the target galaxy and generally detect Mg ii absorption. The Mg ii Doppler shifts have the same sign as the galactic rotation, so the cold gas co-rotates with the galaxy. Because the absorption spans a broader velocity range than disk rotation can explain, we explore simple models for the circumgalactic kinematics. Gas spiraling inwards (near the disk plane) offers a successful description of the observations. An appendix describes the addition of tangential and radial gas flows and illustrates how the sign of the disk inclination produces testable differences in the projected line-of-sight velocity range. This inflow interpretation implies that cold flow disks remain common down to redshift z ≈ 0.2 and prolong star formation by supplying gas to the disk.

Authors:
;  [1];  [2];  [3]
  1. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
  2. Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia)
  3. Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)
Publication Date:
OSTI Identifier:
22663903
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 835; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABSORPTION; DOPPLER EFFECT; EVOLUTION; GALAXIES; GAS FLOW; QUASARS; RED SHIFT; ROTATION; SPECTROSCOPY; STARS; VELOCITY

Citation Formats

Ho, Stephanie H., Martin, Crystal L., Kacprzak, Glenn G., and Churchill, Christopher W., E-mail: shho@physics.ucsb.edu, E-mail: cmartin@physics.ucsb.edu. Quasars Probing Galaxies. I. Signatures of Gas Accretion at Redshift z ≈ 0.2. United States: N. p., 2017. Web. doi:10.3847/1538-4357/835/2/267.
Ho, Stephanie H., Martin, Crystal L., Kacprzak, Glenn G., & Churchill, Christopher W., E-mail: shho@physics.ucsb.edu, E-mail: cmartin@physics.ucsb.edu. Quasars Probing Galaxies. I. Signatures of Gas Accretion at Redshift z ≈ 0.2. United States. doi:10.3847/1538-4357/835/2/267.
Ho, Stephanie H., Martin, Crystal L., Kacprzak, Glenn G., and Churchill, Christopher W., E-mail: shho@physics.ucsb.edu, E-mail: cmartin@physics.ucsb.edu. Wed . "Quasars Probing Galaxies. I. Signatures of Gas Accretion at Redshift z ≈ 0.2". United States. doi:10.3847/1538-4357/835/2/267.
@article{osti_22663903,
title = {Quasars Probing Galaxies. I. Signatures of Gas Accretion at Redshift z ≈ 0.2},
author = {Ho, Stephanie H. and Martin, Crystal L. and Kacprzak, Glenn G. and Churchill, Christopher W., E-mail: shho@physics.ucsb.edu, E-mail: cmartin@physics.ucsb.edu},
abstractNote = {We describe the kinematics of circumgalactic gas near the galactic plane, combining new measurements of galaxy rotation curves and spectroscopy of background quasars. The sightlines pass within 19–93 kpc of the target galaxy and generally detect Mg ii absorption. The Mg ii Doppler shifts have the same sign as the galactic rotation, so the cold gas co-rotates with the galaxy. Because the absorption spans a broader velocity range than disk rotation can explain, we explore simple models for the circumgalactic kinematics. Gas spiraling inwards (near the disk plane) offers a successful description of the observations. An appendix describes the addition of tangential and radial gas flows and illustrates how the sign of the disk inclination produces testable differences in the projected line-of-sight velocity range. This inflow interpretation implies that cold flow disks remain common down to redshift z ≈ 0.2 and prolong star formation by supplying gas to the disk.},
doi = {10.3847/1538-4357/835/2/267},
journal = {Astrophysical Journal},
number = 2,
volume = 835,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}