Distribution of identified absorption features of QSOs at different emission redshifts

It has been reported that absorption features in QSO spectra are more likely to be observed at higher emission redshift (Z/em/) objects. However, no systematic analysis exists to determine the nature of such preferential occurrence, if any, of absorption lines. The analysis shows that the presence of identified absorption lines of QSOs is an exponential function of Z(em). An upper limit has been predicted for the percentage of QSOs showing identified absorption lines at various values of Z(em). Furthermore, results strongly indicate that the appearance of absorbing clouds with individual QSOs is closely associated with the creation of the objects themselves. The two may have a common origin