SHAO Astrophysics Colloquium

Title: MUSEQuBES CGM Surveys: From Low-z Star-forming Galaxies to High-z Lyman-alpha Emitters

Time: 15:00, Mar. 21

Location: Lecture Hall, 3rd floor

Abstract:

Gas accretion and galactic winds are the two most important and yet the most poorly understood ingredients of galaxy evolution models. The physical/chemical conditions of the circumgalactic medium (CGM-- a dynamic, complex, multiphase gas reservoir surrounding galaxies) retain imprints of gas accretion and galactic winds. Moreover, it is now well-established that the metal-enriched, ionized CGM harbors gas and metal masses comparable to those in galaxies themselves and can account for the "missing baryons" in galaxies. Consequently, the CGM has received significant attention from both the theoretical and observational astronomical communities. To this end, we are conducting two major, and by far the largest, surveys on the CGM using ~120 hours of MUSE GTO observations. Our high-z (z > 3) sample comprises ~100 Lyman alpha emitters and the low-z (z < 1) sample comprises ~300 low-mass, star-forming galaxies. We use high S/N spectra of background quasars, obtained with the VLT/UVES (for high-z) and HST/COS (for low-z), to study their CGM using absorption line spectroscopy. An overview of the initial main results of these surveys will be presented in the talk. In particular, the dependence of the CGM properties on the SFR, stellar mass, impact parameter, and on redshift will be discussed.