Atomic and molecular gas in IllustrisTNG galaxies at low redshift
Name
1902.10714.pdf
Description
Accepted version
Size
1.61 MB
Format
Unknown
Checksum (MD5)
42c04f4425c151f5600c2dcc2504faf9
Author(s)
Diemer, Benedikt
Stevens, Adam RH
Lagos, Claudia del P
Calette, AR
Tacchella, Sandro
Hernquist, Lars
Marinacci, Federico
Nelson, Dylan
Pillepich, Annalisa
Rodriguez-Gomez, Vicente
Date Issued
2019
Journal
Monthly Notices of the Royal Astronomical Society
Publisher
Oxford University Press (OUP)
Version
Author's final manuscript
Abstract
ABSTRACT
We have recently developed a post-processing framework to estimate the abundance of atomic and molecular hydrogen (H i and H2, respectively) in galaxies in large-volume cosmological simulations. Here we compare the H i and H2 content of IllustrisTNG galaxies to observations. We mostly restrict this comparison to z ≈ 0 and consider six observational metrics: the overall abundance of H i and H2, their mass functions, gas fractions as a function of stellar mass, the correlation between H2 and star formation rate, the spatial distribution of gas, and the correlation between gas content and morphology. We find generally good agreement between simulations and observations, particularly for the gas fractions and the H i mass–size relation. The H2 mass correlates with star formation rate as expected, revealing an almost constant depletion time that evolves up to z = 2 as observed. However, we also discover a number of tensions with varying degrees of significance, including an overestimate of the total neutral gas abundance at z = 0 by about a factor of 2 and a possible excess of satellites with no or very little neutral gas. These conclusions are robust to the modelling of the H i/H2 transition. In terms of their neutral gas properties, the IllustrisTNG simulations represent an enormous improvement over the original Illustris run. All data used in this paper are publicly available as part of the IllustrisTNG data release.
We have recently developed a post-processing framework to estimate the abundance of atomic and molecular hydrogen (H i and H2, respectively) in galaxies in large-volume cosmological simulations. Here we compare the H i and H2 content of IllustrisTNG galaxies to observations. We mostly restrict this comparison to z ≈ 0 and consider six observational metrics: the overall abundance of H i and H2, their mass functions, gas fractions as a function of stellar mass, the correlation between H2 and star formation rate, the spatial distribution of gas, and the correlation between gas content and morphology. We find generally good agreement between simulations and observations, particularly for the gas fractions and the H i mass–size relation. The H2 mass correlates with star formation rate as expected, revealing an almost constant depletion time that evolves up to z = 2 as observed. However, we also discover a number of tensions with varying degrees of significance, including an overestimate of the total neutral gas abundance at z = 0 by about a factor of 2 and a possible excess of satellites with no or very little neutral gas. These conclusions are robust to the modelling of the H i/H2 transition. In terms of their neutral gas properties, the IllustrisTNG simulations represent an enormous improvement over the original Illustris run. All data used in this paper are publicly available as part of the IllustrisTNG data release.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1093/MNRAS/STZ1323
