Oral Presentation
Growth of Galaxy in the Cold Mode Accretion
Presenter: Pei-Cheng Tung (ASIAA, NTU)
Throughout the history of a galaxy, the interplay between the galaxy, CGM, and IGM is crucial to its evolution and growth. Gas accreted from the CGM and IGM (or cosmic web) cools down and flows into the galaxy, while feedback from stars and the supermassive black hole (SMBH) returns to the CGM, forming an active ecosystem in the star-forming galaxies. Models have suggested that cold accretion should be an effective way to fuel a galaxy and maintain its star formation. With the halo mass smaller than 3e11 solar mass, the heating n contributed by the gravitational potential is weak enough so that cold gas from filaments can flow directly into the galaxy thus enhancing the accretion, which might be a decisive factor in supporting the star formation and the building-up of mass in dwarf galaxy.
In this research, we focus on the accretion of gas from the surrounding environment to the galactic center. We present N-body and hydrodynamical simulations with GIZMO code including physical models such as radiative cooling, star formation, and feedback from star and SMBH. To address the question realistically, we take advantage of the state-of-the-art cosmology simulation, IllustrisTNG, to set the initial conditions. Then, we raise the resolution and implement a set of more sophisticated physical models in our simulation. We examine the physical properties of the accreting CGM gas and study how it affects the evolution of host galaxies. The result shows gas from CGM can make significant impact on the baryon content of the galaxy, including the growth in total mass and the star formation.
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