Effect of Distance Errors: Applications to SDSS Early-Type Galaxies

Abstract

Noisy distance estimates associated with photometric rather than spectroscopic redshifts lead to a mis-estimate of the luminosities, and produce a correlated mis-estimate of the sizes. We consider a sample of early-type galaxies from the SDSS DR6 and apply the generalization of the V_max method to correct for these biases. We show that our technique recovers the true redshift, magnitude and size distributions, as well as the true size-luminosity relation. Regardless the specific application outlined here, our method impacts a broader range of studies, when at least one distance-dependent quantity is involved.

5 pages, 2 figures, to appear in the proceedings of the XLIIIst Rencontres de Moriond, Cosmology, La Thuile, Italy, 15-22 March 2008