Data

Data from: Origin of the galaxy H I size-mass relation

The University of Western Australia
Stevens, Adam ; Diemer, Benedikt ; Lagos Urbina, Claudia ; Nelson, Dylan ; Obreschkow, Danail ; Wang, Jing ; Marinacci, Federico
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://research-repository.uwa.edu.au/en/datasets/c174f382-e406-4e30-8cab-c116b9968f4c&rft.title=Data from: Origin of the galaxy H I size-mass relation&rft.identifier=c174f382-e406-4e30-8cab-c116b9968f4c&rft.publisher=SAO/NASA Astrophysics Data System (ADS)&rft.description=We analytically derive the observed size–mass relation of galaxies’ atomic hydrogen (H I), including limits on its scatter, based on simple assumptions about the structure of H I discs. We trial three generic profiles for H I surface density as a function of radius. First, we assert that H I surface densities saturate at a variable threshold, and otherwise fall off exponentially with radius or, secondly, radius squared. Our third model assumes the total gas surface density is exponential, with the H I fraction at each radius depending on local pressure. These are tested against a compilation of 110 galaxies from the THINGS, LITTLE THINGS, LVHIS, and Bluedisk surveys, whose H I surface density profiles are well resolved. All models fit the observations well and predict consistent size–mass relations. Using an analytical argument, we explain why processes that cause gas disc truncation – such as ram-pressure stripping – scarcely affect the H I size–mass relation. This is tested with the IllustrisTNG(100) cosmological, hydrodynamic simulation and the DARK SAGE semi-analytic model of galaxy formation, both of which capture radially resolved disc structure. For galaxies with m∗ ≥ 109 M and mH I ≥ 108 M, both simulations predict H I size–mass relations that align with observations, show no difference between central and satellite galaxies, and show only a minor, second-order dependence on host halo mass for satellites. Ultimately, the universally tight H I size–mass relation is mathematically inevitable and robust. Only by completely disrupting the structure of H I discs, e.g. through overly powerful feedback, could a simulation predict the relation poorly.&rft.creator=Stevens, Adam &rft.creator=Diemer, Benedikt &rft.creator=Lagos Urbina, Claudia &rft.creator=Nelson, Dylan &rft.creator=Obreschkow, Danail &rft.creator=Wang, Jing &rft.creator=Marinacci, Federico &rft.date=2019&rft.relation=http://research-repository.uwa.edu.au/en/publications/4becd1ec-8fa6-4326-a295-65b4e4b86f20&rft_subject=galaxies: general&rft_subject=galaxies: haloes&rft_subject=galaxies: interactions&rft_subject=galaxies: ISM&rft_subject=Astrophysics - Astrophysics of Galaxies&rft.type=dataset&rft.language=English Access the data

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We analytically derive the observed size–mass relation of galaxies’ atomic hydrogen (H I), including limits on its scatter, based on simple assumptions about the structure of H I discs. We trial three generic profiles for H I surface density as a function of radius. First, we assert that H I surface densities saturate at a variable threshold, and otherwise fall off exponentially with radius or, secondly, radius squared. Our third model assumes the total gas surface density is exponential, with the H I fraction at each radius depending on local pressure. These are tested against a compilation of 110 galaxies from the THINGS, LITTLE THINGS, LVHIS, and Bluedisk surveys, whose H I surface density profiles are well resolved. All models fit the observations well and predict consistent size–mass relations. Using an analytical argument, we explain why processes that cause gas disc truncation – such as ram-pressure stripping – scarcely affect the H I size–mass relation. This is tested with the IllustrisTNG(100) cosmological, hydrodynamic simulation and the DARK SAGE semi-analytic model of galaxy formation, both of which capture radially resolved disc structure. For galaxies with m∗ ≥ 109 M and mH I ≥ 108 M, both simulations predict H I size–mass relations that align with observations, show no difference between central and satellite galaxies, and show only a minor, second-order dependence on host halo mass for satellites. Ultimately, the universally tight H I size–mass relation is mathematically inevitable and robust. Only by completely disrupting the structure of H I discs, e.g. through overly powerful feedback, could a simulation predict the relation poorly.

Notes

External Organisations
Harvard University; Smithsonian Institution; Max Planck Institute for Astrophysics; University of Bologna
Associated Persons
Benedikt Diemer (Creator); Dylan Nelson (Creator); Jing Wang (Creator); Federico Marinacci (Creator)

Issued: 2019-11

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  • global : c174f382-e406-4e30-8cab-c116b9968f4c