Connection between Galaxies and H i in Circumgalactic and Intergalactic Media: Variation according to Galaxy Stellar Mass and Star Formation Activity

This paper systematically investigates comoving Mpc scale intergalactic medium (IGM) environment around galaxies traced by the Ly$\alpha$ forest. Using our cosmological hydrodynamic simulations, we investigate IGM-galaxy connection at $z=2$ two methods: (I) cross-correlation analysis between and fluctuation of forest transmission ($\delta_\text{F}$); (II) comparing overdensity neutral hydrogen (HI) galaxies. Our simulations reproduce observed functions (CCF) Lyman-break We further variation CCF using subsamples divided dark matter halo mass ($M_\text{DH}$), galaxy stellar ($M_\star$), star-formation rate (SFR), find that signal becomes stronger with increasing $M_\text{DH}$, $M_\star$, SFR. The CCFs gas-density are also found to have similar trends. Therefore, $\delta_\text{F}$-CCF depending on SFR is due varying gas density correlation IGM HI distribution strongly depends $M_\text{DH}$ as expected from linear theory. results support $\Lambda$CDM paradigm, finding a spatial HI, more massive being clustered in higher-density regions.