Borthakur, S;
Heckman, T;
Tumlinson, J;
Bordoloi, R;
Kauffmann, G;
Catinella, B;
Schiminovich, D;
... Saintonge, A; + view all
(2016)
The Properties of the Circumgalactic Medium in Red and Blue Galaxies: Results from the COS-GASS+COS-HALOS Surveys.
The Astrophysical Journal
, 833
(2)
, Article 259. 10.3847/1538-4357/833/2/259.
Preview |
Text
Saintonge_Borthakur_2016_ApJ_833_259.pdf - Published Version Download (1MB) | Preview |
Abstract
We use the combined data from the COS-GASS and COS-Halos surveys to characterize the Circum-Galactic Medium (CGM) surrounding typical low-redshift galaxies in the mass range ${M}_{* }\sim \,{10}^{9.5-11.5}\,{M}_{\odot }$, and over a range of impact parameters extending to just beyond the halo virial radius (R vir). We find the radial scale length of the distributions of the equivalent widths of the Lyα and Si iii absorbers to be ~1 and ~0.4 R vir, respectively. The radial distribution of equivalent widths is relatively uniform for the blue galaxies, but highly patchy (i.e., it has a low covering fraction) for the red galaxies. We also find that the Lyα and Si iii equivalent widths show significant positive correlations with the specific star formation rate (sSFR) of the galaxy. We find a surprising lack of correlations between the halo mass (virial velocity) and either the velocity dispersions or velocity offsets of the Lyα lines. The ratio of the velocity offset to the velocity dispersion for the Lyα absorbers has a mean value of ~4, suggesting that a given line of sight is intersecting a dynamically coherent structure in the CGM, rather than a sea of orbiting clouds. The kinematic properties of the CGM are similar in the blue and red galaxies, although we find that a significantly larger fraction of the blue galaxies have large Lyα velocity offsets (>200 km s−1). We show that—if the CGM clouds represent future fuel for star formation—our new results could imply a large drop in the sSFR across the galaxy mass-range we probe.
| Type: | Article |
|---|---|
| Title: | The Properties of the Circumgalactic Medium in Red and Blue Galaxies: Results from the COS-GASS+COS-HALOS Surveys |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/833/2/259 |
| Publisher version: | http://dx.doi.org/10.3847/1538-4357/833/2/259 |
| Language: | English |
| Additional information: | © 2016. The American Astronomical Society. All rights reserved. |
| Keywords: | Galaxies: halos, galaxies: star formation, quasars: absorption lines, High-velocity Clouds, Alpha Absorption Systems, Star-forming Galaxies, Arecibo Sdss Survey, Locally Brightest Galaxies, Fraction Scaling Relations, Absorber Cross-correlation, Metal-line Absorption, Low-redshift Universe, Similar-to 0 |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/1526861 |
Archive Staff Only
 |
View Item |
