Journal
ASTROPHYSICAL JOURNAL
Volume 733, Issue 2, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0004-637X/733/2/105
Keywords
galaxies: halos; galaxies: kinematics and dynamics; intergalactic medium; quasars: absorption lines
Categories
Funding
- NSF [AST-0708210, AST-1009999]
- UC Irvine Center for Cosmology
- Gary McCue Postdoctoral Fellowship
- W. M. Keck Foundation
- Alfred P. Sloan Foundation
- National Science Foundation
- U.S. Department of Energy
- National Aeronautics and Space Administration
- Japanese Monbukagakusho
- Max Planck Society
- Higher Education Funding Council for England
- American Museum of Natural History
- Astrophysical Institute Potsdam
- University of Basel
- University of Cambridge
- Case Western Reserve University
- University of Chicago
- Drexel University
- Fermilab
- Institute for Advanced Study
- Japan Participation Group
- Johns Hopkins University
- Joint Institute for Nuclear Astrophysics
- Kavli Institute for Particle Astrophysics and Cosmology
- Korean Scientist Group
- Chinese Academy of Sciences (LAMOST)
- Los Alamos National Laboratory
- Max-Planck-Institute for Astronomy (MPIA)
- Max-Planck-Institute for Astrophysics (MPA)
- New Mexico State University
- Ohio State University
- University of Pittsburgh
- University of Portsmouth
- Princeton University
- United States Naval Observatory
- University of Washington
- Division Of Astronomical Sciences
- Direct For Mathematical & Physical Scien [1009999] Funding Source: National Science Foundation
Ask authors/readers for more resources
We have directly compared Mg II halo gas kinematics to the rotation velocities derived from emission/absorption lines of the associated host galaxies. Our 0.096 <= z <= 0.148 volume-limited sample comprises 13 similar to L-* galaxies, with impact parameters of 12-90 kpc from background quasar sight lines, associated with 11 Mg II absorption systems with Mg II equivalent widths 0.3 angstrom <= W-r(2796) <= 2.3 angstrom. For only 5/13 galaxies, the absorption resides to one side of the galaxy systemic velocity and trends to align with one side of the galaxy rotation curve. The remainder have absorption that spans both sides of the galaxy systemic velocity. These results differ from those at z similar to 0.5, where 74% of the galaxies have absorption residing to one side of the galaxy systemic velocity. For all the z similar to 0.1 systems, simple extended disk-like rotation models fail to reproduce the full Mg II velocity spread, implying that other dynamical processes contribute to the Mg II kinematics. In fact 55% of the galaxies are counter-rotating with respect to the bulk of the Mg II absorption. These Mg II host galaxies are isolated, have low star formation rates (SFRs) in their central regions (less than or similar to 1M(circle dot) yr(-1)), and SFRs per unit area well below those measured for galaxies with strong winds. The galaxy Na ID (stellar+ISM) and Mg Ib (stellar) absorption line ratios are consistent with a predominately stellar origin, implying kinematically quiescent interstellar media. These facts suggest that the kinematics of the Mg II absorption halos for our sample of galaxies are not influenced by galaxy-galaxy environmental effects, nor by winds intrinsic to the host galaxies. For these low-redshift galaxies, we favor a scenario in which infalling gas accretion provides a gas reservoir for low-to-moderate SFRs and disk/halo processes.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available