The MgII Cross-section of Luminous Red Galaxies

Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Accepted by ApJ; minor corrections

Scientific paper

We describe a search for MgII(2796,2803) absorption lines in Sloan Digital Sky Survey (SDSS) spectra of QSOs whose lines of sight pass within impact parameters of 200 kpc of galaxies with photometric redshifts of z=0.46-0.6 and redshift errors Delta z~0.05. The galaxies selected have the same colors and luminosities as the Luminous Red Galaxy (LRG) population previously selected from the SDSS. A search for Mg II lines within a redshift interval of +/-0.1 of a galaxy's photometric redshift shows that absorption by these galaxies is rare: the covering fraction is ~ 10-15% between 20 and 100 kpc, for Mg II lines with rest equivalent widths of Wr >= 0.6{\AA}, falling to zero at larger separations. There is no evidence that Wr correlates with impact parameter or galaxy luminosity. Our results are consistent with existing scenarios in which cool Mg II-absorbing clouds may be absent near LRGs because of the environment of the galaxies: if LRGs reside in high-mass groups and clusters, either their halos are too hot to retain or accrete cool gas, or the galaxies themselves - which have passively-evolving old stellar populations - do not produce the rates of star formation and outflows of gas necessary to fill their halos with Mg II absorbing clouds. In the rarer cases where Mg II is detected, however, the origin of the absorption is less clear. Absorption may arise from the little cool gas able to reach into cluster halos from the intergalactic medium, or from the few star-forming and/or AGN-like LRGs that are known to exist.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

The MgII Cross-section of Luminous Red Galaxies does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The MgII Cross-section of Luminous Red Galaxies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The MgII Cross-section of Luminous Red Galaxies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-586483

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.