2016/05/05 by Jing Wang, Bärbel S. Koribalski, B. Koribalski +8 · 1 citation
Physics and Astronomy · #Accretion (finance) #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Dwarf galaxy #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Lenticular galaxy #Luminosity #Physics #RADIUS #Sigma #Spiral galaxy #astro-ph.GA
paper · pdf · doi:10.1093/mnras/stw1099
9 pages, 6 figures, accepted for publication at MNRAS
arxiv created 2016/05/05 · openalex publication_date 2016/05/11 · arxiv updated 2016/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We revisit the H i size–mass (|D_\rm H \small 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.