We present a semi-analytical model to test the hypothesis that Ly-alpha QSO absorption lines originate in gaseous halos produced by multiple supernova explosions occurring in Pop III objects in a CDM cosmological scenario hoping to assess the validity of CDM models and/or constrain their parameters. The preliminary results indicate that the range of $N_{ HI}$, redshift distribution and metallicity of clouds are well reproduced by CDM if they are associated with galaxy halos or groups. Firm conclusions on clouds with $N_{ HI}\le 10^{ 14} cm^{ -2}$ need a more refined study.
Categories: astro-ph