Pre-submission Thesis Presentation
A study of physical processes in galaxies and circumgalactic medium
Speaker: Mukesh Singh Bisht R (PhD Student, A&A Group, RRI)
The circumgalactic medium (CGM) is the vast gaseous atmosphere that surrounds galaxies. It plays a crucial role in galaxy evolution by recycling material expelled through galactic outflows and by regulating the accreted gas from the intergalactic medium (IGM). Observations and simulations show that the Milky Way’s (MW) CGM is multiphase, with temperatures ranging from the cool phase (∼ 104 K) to the virial phase (∼ 106 K). While the origins of these phases are relatively well understood, the detection of an even hotter component (∼ 107 K) is particularly intriguing.
This so-called ‘super-virial’ phase, observed in both X-ray emission and absorption, remains poorly understood in terms of its origin, spatial distribution, and chemical composition. In this presentation, I will discuss the possible origins and physical characteristics of this hot component along with an X-ray absorption study of this gas towards the blazar PKS 2155-304. In the latter part, I will also address the observational properties and spatial distribution of the cool gas in the CGM.