Strong Evolution in the Luminosity-Velocity Relation at z>1?
Abstract
We present a method for constraining the evolution of the galaxy luminosity-velocity (LV) relation in hierarchical scenarios of structure formation. The comoving number density of dark-matter halos with circular velocity of 200 km/s is predicted in favored CDM cosmologies to be nearly constant over the redshift range 0<z<5. Any observed evolution in the density of bright galaxies implies in turn a corresponding evolution in the LV relation. We consider several possible forms of evolution for the zero-point of the LV relation and predict the corresponding evolution in galaxy number density. The Hubble Deep Field suggests a large deficit of bright (M_V < -19) galaxies at 1.4 < z < 2. If taken at face value, this implies a dimming of the LV zero-point by roughly 2 magnitudes. Deep, wide-field, near-IR selected surveys will provide more secure measurements to compare with our predictions.
Cite
@article{arxiv.astro-ph/0005325,
title = {Strong Evolution in the Luminosity-Velocity Relation at z>1?},
author = {James S. Bullock and Avishai Dekel and Joel R. Primack and Rachel S. Somerville},
journal= {arXiv preprint arXiv:astro-ph/0005325},
year = {2009}
}
Comments
4 pages, 2 figures. Submitted to ApJ Letters