The relation between specific baryon angular momentum and mass for a sample of nearby low-mass galaxies with resolved H I kinematics
Abstract
This paper investigates the relationship between specific baryon angular momentum jb and baryon mass Mb for a sample of nearby late-type galaxies with resolved H I kinematics. This work roughly doubles the number of galaxies with Mb ≲ 1010 M⊙ used to study the jb-Mb relation. Most of the galaxies in the sample have their baryon mass dominated by their gas content, thereby offering jb and Mb measures that are relatively unaffected by uncertainties arising from the stellar mass-to-light ratio. Measured H I surface density radial profiles together with optical and rotation curve data from the literature are used to derive a best-fitting relation given by j_b=qM_b^{α }, with α = 0.62 ± 0.02 and log10 q = -3.35 ± 0.25. This result is consistent with the j_b∝ M_b^{2/3} relation that is theoretically expected and also measured by Obreschkow & Glazebrook for their full sample of THINGS spiral galaxies, yet differs to their steeper relation found for subsets with fixed bulge fraction. The 30 arcsec spatial resolution of the H I imaging used in this study is significantly lower than that of the THINGS imaging used by Obreschkow & Glazebrook, yet the results presented in this work are clearly shown to contain no significant systematic errors due to the low-resolution imaging.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2017
- DOI:
- 10.1093/mnras/stx2313
- arXiv:
- arXiv:1709.03288
- Bibcode:
- 2017MNRAS.472.4551E
- Keywords:
-
- galaxies: evolution;
- galaxies: fundamental parameters;
- galaxies: evolution - galaxies: fundamental parameters;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- MNRAS, in press