Circumgalactic Medium in Starburst Galaxies

Event Date: 

Wednesday, August 29, 2012 - 4:00pm

Event Location: 

  • Broida Conference Room 3302

Event Contact: 

Crystal Martin

Speaker:

Sanch Borthakur

The circum-galactic medium (CGM) of a galaxy is its gas reservoir and holds clues to its past and future evolution. I will present some of our recent work aimed at understanding the effects of starburst on the CGM. In this study, we used UV bright background QSOs to probe the CGM in foreground galaxies. We used the occurrence of CIV as an indicator for the presence of hot gas. Our comparison of the properties of the CGM in starburst (SB) and post-starburst (PSB) galaxies to normal galaxies with similar stellar masses and impact parameters revealed a much larger incidence rate of hot gas in SB and PSB galaxies. These galaxies display strong CIV transitions. On the other hand, their CII and SiII are barely detectable. In fact, even HI Lyman alpha transition was observed to be much weaker than CIV in SB and PSB galaxies. Our study also suggests that a starburst event heats the CGM at a time-scale of 100 Myrs to 1 Gyrs. This may help in understanding how galaxies regulate their star formation activity.