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The Stochastic Effect of Ly-alpha absorbers on Broadband Luminosities of Galaxies

T. Tepper Garcia·U. Fritze-v. A
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Abstract

We investigate the variations of broadband luminosities of low and intermediate redshift galaxies due to the stochastic nature of the neutral hydrogen present in form of Ly-alpha 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 and calculate attenuated FUV/NUV magnitudes and corresponding 1-, 2- and 3-sigma variations. We predict significant variations in luminosity ranging from -0.22 to +0.48 magnitudes at the 1-sigma level for galaxies at z=1.5 in GALEX data.

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T. Tepper Garcia, U. Fritze-v. A. 2005-04-25. The Stochastic Effect of Ly-alpha absorbers on Broadband Luminosities of Galaxies. https://doi.org/10.1017/s1743921305003145

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