Oral Presentation

Probing Cool Gas and Feedback in Massive Halos

Author(s):

Presenter: Ting-Wen Lan (National Taiwan University)

The hot circumgalactic and intracluster medium in galaxy groups and clusters has been extensively studied through multiwavelength observations, including X-ray and thermal Sunyaev–Zel'dovich (tSZ) measurements. In contrast, the presence and properties of cool gas (~10⁴ K) in these massive environments remain poorly understood. In this talk, I will first review the current understanding of cool gas in such massive halos. I will then present new results on the redshift evolution of the cool gas in halos with ~10^13 M_sun traced by luminous red galaxies (LRGs) observed by the Dark Energy Spectroscopic Instrument (DESI). Additionally, I will explore the impact of radio-mode feedback—a key mechanism for regulating thermal balance in massive halos—on the distribution of the cool gas. Finally, I will discuss the broader implications of these findings for our understanding of galaxy evolution in dense environments.