New lessons from the H I size-mass relation of galaxies

Journal
Date Issued
2016
Author(s)
Wang, Jing
•
Koribalski, Bärbel S.
•
•
van der Hulst, Thijs
•
Roychowdhury, Sambit
•
Kamphuis, Peter
•
Chengalur, Jayaram N.
DOI
Abstract
We revisit the H I size-mass (D_{H I}-MH I) relation of galaxies with a sample of more than 500 nearby galaxies covering over five orders of magnitude in H I mass and more than 10 B-band magnitudes. The relation is remarkably tight with a scatter σ ∼ 0.06 dex, or 14 per cent. The scatter does not change as a function of galaxy luminosity, H I richness or morphological type. The relation is linked to the fact that dwarf and spiral galaxies have a homogeneous radial profile of H I surface density in the outer regions when the radius is normalized by DH I. The early-type disc galaxies typically have shallower H I radial profiles, indicating a different gas accretion history. We argue that the process of atomic-to-molecular gas conversion or star formation cannot explain the tightness of the DH I-MH I relation. This simple relation puts strong constraints on simulation models for galaxy formation.
Volume
460
Issue
2
Start page
2143
Uri
Url
Issn Identifier
0035-8711
Ads BibCode
2016MNRAS.460.2143W
Rights
open.access
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