The stochastic effects of Lyα absorbers on the broadband luminosities of galaxies

We investigate the variations in the broadband luminosities of low and intermediate redshift galaxies due to the stochastic nature of the neutral hydrogen distribution present in the form of Lyα absorbers in the intergalactic medium. This effect is caused by variations in the distribution and properties (redshift, column density, doppler parameter) of the absorbers along different lines-of-sight out to a given redshift. Using a set of observationally constrained redshift-, column density-, and doppler parameter distributions we perform monte carlo simulations for a large number of lines-of-sight towards galaxies at a given redshift z_em and calculate attenuated FUV/NUV magnitudes and corresponding 1-, 2-, and 3σ variations. We predict significant variations in luminosity ranging from -0.22 to +0.48 magnitudes at the 1σ level for galaxies at z=1.5 in galex data.