I am working on the circumgalactic medium (CGM). Hover over the pages under "Research" to look for details about each project/paper led by me.

CGM is the diffuse gaseous medium around the galactic disk, filling up the volume of the dark matter halo the galaxy resides in. It is composed of different components: the cold gas accreted from the intergalactic filaments; the metal-enriched hot outflows from the galaxy; and a mix of these two, which can stay in the halo or leave the halo and join the intergalactic medium (IGM) or precipitate back (recycled) to the galaxy disk. This explains the multi-phase nature of CGM, which spans a large range of temperature and density. The CGM can be studied from two different perspectives. It can be considered as a baryonic (and metallic) complement to the galactic disk in the disk-halo system. The formation and evolution, and hence, the physical and chemical properties of the disk and the halo are codependent. As the disk components (interstellar medium, stars, and nucleus) have been being studied in more detail compared to the halo gas, usually the CGM characteristics are viewed as a function of the disk properties (e.g., how different the CGM of spirals and ellipticals are, or how the relative abundance of different CGM phases depends on the star formation rate, black hole feedback etcetera). The problems of missing metals and missing feedback are framed from the point of view of the disk's activities; and when the disk-halo system is considered as a whole, CGM stands as a possible solution. Also, the neutral CGM holds clues about the accretion which is essential to the star formation in a galaxy.  On the other hand, the galaxy can be observed as a dynamic system and its CGM can be studied from a cosmological point of view. In this case, the virial properties of the galaxy are the primary factors. At low redshift, only a small fraction of the expected baryons are found in the disk of the galaxies. It is an important question whether the baryon to dark matter ratio in an individual galaxy is the same as the ratio in larger dynamical systems like galaxy groups and galaxy clusters. CGM and IGM are the primary candidates for these missing baryons.