Colloq Abstract -Lehner

by Hubertus Intema last modified Sep 12, 2017 by Lori Appel

Sep 22

11:00am Mountain

 

Nicolas Lehner (Univ. of Notre Dame)

 

Finding the Large Reservoirs of Gas Around Galaxies

 

Abstract

Our modern understanding of galaxy evolution relies heavily on the exchange of matter between galaxies and the intergalactic medium (IGM) to explain a broad range of observable galaxy properties. The competition between mass gain (via accretion) and loss (via outflows) plays out in the circumgalactic medium (CGM). Gas flows through the CGM directly influence the baryon distribution and metal content of their host galaxies as well as the level of stellar activity in the disk, and hence the evolution of galaxies. Here I will discuss some of the recent surveys that have transformed our view of the CGM in the last ~5 years. I will present some future directions in this field and in particular the need for future radio 21-cm HI emission survey to be sensitive to very low HI column densities.