Weighing Galaxy Disks With the Baryonic Tully-Fisher Relation
Abstract
We estimate the stellar masses of disk galaxies with two independent methods: a photometrically self-consistent color-mass-to-light ratio relation (CMLR) from population synthesis models, and the baryonic Tully-Fisher relation (BTFR) calibrated by gas-rich galaxies. These two methods give consistent results. The CMLR correctly converts distinct Tully-Fisher relations in different bands into the same BTFR. The BTFR is consistent with {{M}b}\propto Vf4 over nearly six decades in mass, with no hint of a change in slope over that range. The intrinsic scatter in the BTFR is negligible, implying that the IMF of disk galaxies is effectively universal. The gas-rich BTFR suggests an absolute calibration of the stellar mass scale that yields nearly constant mass-to-light ratios in the near-infrared (NIR): 0.57 {{M}}/{{L}} in Ks and 0.45 {{M}}/{{L}} at 3.6 μm. There is only modest intrinsic scatter (∼0.12 dex) about these typical values. There is no discernible variation with color or other properties: the NIR luminosity is a good tracer of stellar mass.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2015
- DOI:
- 10.1088/0004-637X/802/1/18
- arXiv:
- arXiv:1501.06826
- Bibcode:
- 2015ApJ...802...18M
- Keywords:
-
- galaxies: evolution;
- galaxies: fundamental parameters;
- galaxies: kinematics and dynamics;
- galaxies: photometry;
- galaxies: stellar content;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- Accepted for publication in the Astrophysical Journal. 6 figures, 5 tables, 17 pages