Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics
Scientific paper
2011-08-19
Astronomy and Astrophysics
Astrophysics
Cosmology and Extragalactic Astrophysics
7 pages, 3 figures, 1 table. Accepted for publication in MNRAS
Scientific paper
We present a spectroscopic sample of z \approx 0.5 luminous red galaxies (LRGs) that are located within physical projected distances \rho \leq 350 kpc/h of a QSO sightline. Of the 37 LRGs in our sample, eight have associated MgII absorbers with rest-frame equivalent width Wr(2796)>0.3A and velocity separation |dv| \leq 350 km/s and 29 do not have associated MgII absorbers to a 2-sigma limit of Wr(2796)=0.3A. We perform a stellar population synthesis analysis using stacked spectra of the MgII absorbing and non-absorbing LRG subsamples. We find that LRGs with or without associated MgII absorbers share similar star formation histories and are best described by old stellar population models (\geq 1 Gyr). Younger stellar populations (\leq 1 Gyr) fail to reproduce their spectra. These findings are consistent with the lack of [OII] emission features in the LRG spectra. The primarily old stellar populations in the LRGs indicate that starburst driven outflows are unlikely to explain the observed MgII absorbers at large distances from the LRGs. In addition, the spectroscopic LRG sample allows us to derive a sensitive constraint for the cool gas covering fraction of <\kappa>=14 +/- 6% in the LRG halos for absorbers of Wr(2796)>0.3A. Finally, we speculate on the origin of the observed MgII absorbers around the LRGs.
Chen Hsiao-Wen
Gauthier Jean-Rene
No associations
LandOfFree
The Star Formation History of Luminous Red Galaxies Hosting MgII Absorbers 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 Star Formation History of Luminous Red Galaxies Hosting MgII Absorbers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Star Formation History of Luminous Red Galaxies Hosting MgII Absorbers will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-244166