I review our recent results concerning the metal abundances in quasar absorption-line spectra obtained with the UVES/VLT , HIRES/ KECK , and STIS/HST spectrographs .
The analysis is based on the Monte Carlo inversion procedure aimed at the restoring the physical parameters and the 1D distributions of the velocity and density fields in quasar absorbers .
A functional dependence of the line-of-sight velocity dispersion , \sigma _ { v } , on the absorber linear size , L , was found : the majority of the analyzed systems follow the scaling relation \sigma _ { v } \sim ( N _ { H } L ) ^ { 0.3 } ( with N _ { H } being the total gas column density ) .
This may indicate that the metal absorbers are associated with virialized systems like galaxies or their halos .
A metal content enhancement ( up to Z \sim 4 Z _ { \odot } ) was observed in small-size absorbers ( L \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$ } } } \hbox { $ < $ } } } 0.4 kpc ) , whereas decreasing metal abundances were found in systems with increasing L .
The lowest metallicity ( [ C/H ] \simeq - 3.0 ) was detected in the z _ { abs } = 2.917 Lymna-limit system ( LLS ) with N ( H i ) = 3.2 \times 10 ^ { 17 } cm ^ { -2 } and L \simeq 140 kpc .
The relative abundance ratio of [ Si/C ] \simeq 0.35 , measured in this LLS , seems to indicate that the initial mass function for the stellar population , produced the observed metallicity pattern , was constrained to intermediate masses , M _ { up } \mathrel { \hbox { \hbox to 0.0 pt { \hbox { \lower 4.0 pt \hbox { $ \sim$ } } } \hbox% { $ < $ } } } 25 M _ { \odot } .