Abstract Details

Name: Prakriti Pal Choudhury
Affiliation: Indian Institute of Science
Conference ID: ASI2020_245
Title : Multiphase gas in the circumgalactic medium
Authors and Co-Authors : Prakriti Pal Choudhury, Prateek Sharma, Eliot Quataert
Abstract Type : Oral
Abstract Category : Extragalactic Astronomy
Abstract : Multi-wavelength observations detect gas within dark matter halos in various thermodynamic and dynamical states. Broadly, the gas is in three primary dynamical states: firstly, in-falling into the potential well of the halo; secondly, remains within the halo in (quasi)hydrostatic equilibrium until it radiatively cools; thirdly, gets ejected from the halo by strong outflows (feedback) driven by a central black hole or stars. The gas within the halos and outside the central galaxy (hosting the black hole and stars) is called the circumgalactic medium (CGM), and specifically, intracluster medium (ICM) in the most massive halos (~ 10^{14} solar mass). Observations indicate that the ICM does not cool as efficiently as predicted in the theory including pure radiative cooling. Radio, X-ray and H-alpha observations now suggest that the central black hole is injecting a copious amount of energy in clusters to maintain a rough global thermal balance. Using results from theory and idealized numerical simulations, I will discuss how locally thermally unstable ICM becomes multiphase (temperature ranges: 10^4 - 10^7 K). I will also discuss that the entropy profiles of the hot gas gets reset by cooling/feedback and may modify the nature of multiphase condensation. Lastly, I will mention the ongoing works on the CGM using a novel numerical set-up.