Galactic Accretion through the CGM
How do galaxies get their gas?
Galaxies must obtain fresh gas from their surroundings to convert into stars and grow in mass over time. However, it is debated in what form this gas arrives at the galaxy: hot or cold, spherically symmetrically or in filaments, smoothly over time or in short bursts. I am currently using the Figuring Out Gas & Galaxies In Enzo (FOGGIE) simulations to investigate the properties of gas accretion through the circumgalactic medium (CGM). These simulations resolve the CGM to a high degree, which reveals significant gas kinematics (which are responsible for upsetting equilibrium in the CGM) that may disrupt the filamentary accreting gas flows. I am finding that the filaments do not stream smoothly onto the galaxy and are instead dissipated before reaching it, perhaps by the strong turbulence in the CGM gas near the galaxy.
The animation above shows a visualization of these filaments' location, color-coded by their temperature, for one of the FOGGIE galaxies at z = 0.
