GECO GALAXY EVOLUTION CIRCLE What is the CGM – Lyman-α connection and why should we care?

This time we will have the presence of Duarte Santos, Simon Weng and Teng Hu who will present the topic (abstract below) and encourage the debate. The idea is to continue with a round table format, with a lively and informal discussion from basic to advanced subjects.

Abstract:

The circumgalactic medium (CGM), defined as the region separating the interstellar medium from the intergalactic medium, is the venue for physical processes such as gas accretion and star-formation or AGN-driven outflows. Hence, to understand how galaxies form and evolve, we need to study this crucial component of galaxies across cosmic time. There are many ways to do this, but the probe we focus on in this Circle is the Lyman-α forest. We are going to introduce the Lyman-α forest and how its different level of absorption relates to galaxies, and afterwards mention its detection potential in the nearby Universe. Afterwards, we will move to Cosmic Noon and talk about a particular class of absorbers, called Strong, Blended Lyman-α (SBLA) absorbers, and discuss their potential for finding galaxies both in observations and simulations, using simple methods of detection as well as more sophisticated machine learning algorithms.