The Masses of Distant Galaxies from Optical Emission Line Widths
Abstract
Promising methods for studying galaxy evolution rely on optical emission line width measurements to compare intermediate-redshift objects to galaxies with equivalent masses at the present epoch. However, emission lines can be misleading. We show empirical examples of galaxies with concentrated central star formation from a survey of galaxies in pairs; HI observations of these galaxies indicate that the optical line emission fails to sample their full gravitational potentials. We use simple models of bulge-forming bursts of star formation to demonstrate that compact optical morphologies and small half-light radii can accompany these anomalously narrow emission lines; thus late-type bulges forming on rapid (0.5-1 Gyr) timescales at intermediate redshift would exhibit properties similar to those of heavily bursting dwarfs. We conclude that some of the luminous compact objects observed at intermediate and high redshift may be starbursts in the centers of massive galaxies and/or bulges in formation.
Keywords
Cite
@article{arxiv.astro-ph/0201274,
title = {The Masses of Distant Galaxies from Optical Emission Line Widths},
author = {Elizabeth Barton Gillespie and Liese van Zee},
journal= {arXiv preprint arXiv:astro-ph/0201274},
year = {2009}
}
Comments
6 pages, 4 figures, to appear in the proceedings of the ESO Workshop, "The Mass of Galaxies at Low and High Redshift", eds. R. Bender and A. Renzini