Investigation of neutral hydrogen distribution and neutral hydrogen halo mass relation based on IllustrisTNG50

Abstract

For the sake of investigating the observational data of the universe mass distribution using neutral hydrogen as a mass tracer, it is necessary to investigate the simulation prediction of the distribution of the neutral hydrogen. In this paper, the TNG50 is selected, which is the latest released part of IllustrisTNG project, as simulation data to study the distribution of gas and neutral hydrogen as well as the relation between the halo mass and the corresponding neutral hydrogen mass contained in each halo. The results show a tendency that most of neutral hydrogen are distributed within the halo and sub-halo structures. The neutral hydrogen halo mass relation is clearly shown and the function can be will produced by the conventional HI halo mass parameterization function. Based on the analysis, this paper fills the blank of other related works with most recent TNG50 data. These results offer a guideline for the following study about the halo model and pave a path to deeper understanding and investigating the hydrogen distribution in the cosmos.