The Tully-Fisher Relation of COLD GASS Galaxies
  We present the stellar mass (M_*) and Wide-Field Infrared Survey Explorer
(WISE) absolute Band 1 magnitude (M_W1) Tully-Fisher relations (TFRs) of
subsets of galaxies from the CO Legacy Database for the Galex Arecibo SDSS
Survey (COLD GASS). We examine the benefits and drawbacks of several commonly
used fitting functions in the context of measuring CO(1-0) line widths (and
thus rotation velocities), favouring the Gaussian Double Peak function. We find
the M_W1 and M_* TFR, for a carefully selected sub-sample, to be M_W1 = (-7.1
+/- 0.6) [log(W_50/sin i) - 2.58] - 23.83 +/- 0.09 and log(M_*/M_Sun) = (3.3
+/- 0.3) [log(W_50/sin i) - 2.58] + 10.51 +/- 0.04, respectively, where W_50 is
the width of a galaxy's CO(1-0) integrated profile at 50% of its maximum and
the inclination i is derived from the galaxy axial ratio measured on the SDSS
r-band image. We find no evidence for any significant offset between the TFRs
of COLD GASS galaxies and those of comparison samples of similar redshifts and
morphologies. The slope of the COLD GASS M_* TFR agrees with the relation of
Pizagno et al. (2005). However, we measure a comparatively shallower slope for
the COLD GASS M_W1 TFR as compared to the relation of Tully & Pierce (2000). We
attribute this to the fact that the COLD GASS sample comprises galaxies of
various (late-type) morphologies. Nevertheless, our work provides a robust
reference point with which to compare future CO TFR studies.
