On the dependence between UV luminosity and Lyman-alpha equivalent width in high redshift galaxies

Kim K. Nilsson, Ole Moeller-Nilsson, Palle Moeller, Johan P. U. Fynbo, Alice E. Shapley

Published 2009-07-21Version 1

We show that with the simple assumption of no correlation between the Ly-alpha equivalent width and the UV luminosity of a galaxy, the observed distribution of high redshift galaxies in an equivalent width - absolute UV magnitude plane can be reproduced. We further show that there is no dependence between Ly-alpha equivalent width and Ly-alpha luminosity in a sample of Ly-alpha emitters. The test was expanded to Lyman-break galaxies and again no dependence was found. Simultaneously, we show that a recently proposed lack of large equivalent width, UV bright galaxies (Ando et al. 2006) can be explained by a simple observational effect, based on too small survey volumes.