2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/12947We present new statistical study on the origin of Lyman-alpha absorption systems that are detected in QSO fields. The primary objective is to investigate environmental dependence of the relationship between galaxies and Lyman-alpha absorption systems. We find that galaxies exhibit no environmental dependence in giving rise to Lyman-alpha absorbers in their halos. Conversely, Lyman-alpha absorbers do not exhibit preference as to the environment where they reside.4 pages, 1 figure, to appear in proceedings of the Xth Rencontres de Blois on "The Birth of Galaxies," LaTex style file includedAstrophysicstext