Abstract
We present new measures of the evolving scaling relations between stellar
mass, rotational velocity, magnitude, and baryonic mass estimates for a
morphologically-inclusive sample of 129 disk-like galaxies selected with zAB <
22.5 in the redshift range 0.2 < z < 1.3, based on deep spectra from the DEIMOS
instrument on the Keck II 10 meter telescope, multi-color HST ACS photometry,
and ground-based Ks-band imaging. A unique feature of our survey is the use of
extended integration times for the spectroscopy which has led to significant
improvements in determining characteristic rotational velocities for each
galaxy and a rigorous appraisal of their accuracy. Rotation curves are reliably
traced to the radius where they begin to flatten for ~90% of our sample, and we
model the HST resolved bulge and disk components of each galaxy in order to
accurately de-project our measured velocities while accounting for seeing,
dispersion and slit effects. We demonstrate the merit of these advances by
recovering an intrinsic scatter on the stellar mass Tully-Fisher relation a
factor of 2-3 less than in previous studies at intermediate redshift and
comparable to that of locally-determined relations. With this increased
precision, we show evidence for modest evolution in the stellar mass
Tully-Fisher relation, \Delta M~ 0.14 0.11 dex from <z> ~ 1 to <z> ~
0.3, a growth rate in agreement with recent hydrodynamical and semi-analytic
predictions. Greater evolution is seen in the B-band magnitude Tully-Fisher
relation consistent with a decline in disk luminosity of 0.80 0.16
magnitudes at fixed velocity over the same redshift interval. We use our
dynamical and stellar mass data to evaluate the likely contributions of baryons
and dark matter within our characteristic disk radius and discuss the physical
implications for the assembly history of spiral galaxies.
Users
Please
log in to take part in the discussion (add own reviews or comments).