Astronomy and Astrophysics Seminars

Probing the "Baryon Cycle" using Quasar Absorption Line Spectroscopy

by Dr. Sowgat Muzahid (Leiden Observatory, The Netherlands)

Monday, December 18, 2017 from to (Asia/Kolkata)
at DAA SEMINAR ROOM ( A269 )
TIFR
Description
More than 90% of the cosmic baryons reside outside of galaxies, at any epoch, in a diffuse phase that is too tenuous to detect in emission. Quasar absorption line spectroscopy is a proven technique to probe the otherwise invisible, diffuse gas in the intergalactic medium (IGM), circumcluster medium (CCM), and in the circumgalactic medium (CGM). The UV/optical absorption line features of hydrogen (HI) and heavy elements (metals) arising from these media provide a record of how galaxies acquire, expel, and recycle their gas. The baryon cycle (gas accretion, galactic winds, and recycling of baryons) process is a crucial and yet poorly understood ingredient of galaxy evolution models. In the talk, I will present an overview of our recent and ongoing campaigns on probing the baryon cycle in low-z (z < 1) galaxies and in high-z  (z > 3) Lyman-alpha emitters, using spectral and imaging data obtained with the HST (COS, ACS, WFPC2),  VLT (MUSE, UVES), and Keck (HIRES, ESI) telescopes. The prospects of such studies, with the advent of upcoming next-generation facilities, such as TMT, will also be discussed briefly.