Evolution of the Near-Infrared Tully-Fisher Relation: Constraints on the Relationship between the Stellar and Total Masses of Disk Galaxies since z~1

Using a combination of Keck spectroscopy and near-infrared imaging, we investigate the K-band and stellar-mass Tully-Fisher relation for 101 disk galaxies at 0.2<z<1.2, with the goal of placing the first observational constraints on the assembly history of halo and stellar mass. Our main result is a lack of evolution in either the K-band or stellar-mass Tully-Fisher relation from z=0 to 1.2. Furthermore, although our sample is not statistically complete, we consider it suitable for an initial investigation of how the fraction of total mass that has condensed into stars is distributed with both redshift and total halo mass. We calculate stellar masses from optical and near-infrared photometry and total masses from maximum rotational velocities and disk scale lengths, utilizing a range of model relationships derived analytically and from simulations. We find that the stellar/total mass distribution and stellar-mass Tully-Fisher relation for z>0.7 disks is similar to that at lower redshift, suggesting that baryonic mass is accreted by disks along with dark matter at z<1 and that disk galaxy formation at z<1 is hierarchical in nature. We briefly discuss the evolutionary trends expected in conventional structure formation models and the implications of extending such a study to much larger samples.