类星体Lα森林吸收线密度与发射红移相关性的再考察

继文1]之后,本文利用15个中—高红移类星体的Lα森林构成统计样本,再度考察了Lα森林吸收线密度N(Z_(abs))与发射红移Z_(em)的相关性。本文的统计样本包含的红移范围比文1]更大:类星体的发射红移值从1.715到3.750,Lα森林吸收线红移范围从1.501到3.780;统计方法亦与文1]略有差异。统计结果再度表明,Lα森林吸收线密度N(Z_(abs))明显依赖于类星体自身的发射红移Z_(em),这不仅在于Z_(em)越大的类星体其全部吸收线的平均数密度N(Z_(abs))也越大,更重要的是,对于相同的吸收红移值Z_(abs)而言,N(Z_(abs))在统计意义上明显地随Z_(em)的增大而增大。文末对所得的结果作了讨论。

RE-EXAMINATION OF THE CORRELATION BETWEEN THELYMAN-ALPHA ABSORPTION LINE DENSITY ANDTHE EMISSION REDSHIFT OF QSOs

Bian Yulin et al. (1986) studied the probable correlation between the La line density N(zaba) and the emission redshift zem of the QSO itself, based on a statistical analysis of 16 QSOs' La forests. It shows that the line density of the La forest is clearly dependent on the emission redshift zem of the QSO itself.In this paper, we re-examine the probable correlation between absorption line density V(zabg) and the QSOs' redshift zem based on a new sample consisting of 15 QSOs' La forests quoted from Paper 1] or Paper 2] or from both. The new sample is better than that of Paper 1] in the sense that not only the total number of absorption lines involved are larger but the ranges of both absorption and emission redshift are even more so. The results clearly support the conclusions in Paper 1] .(1) The density of absorption lines in QSOs' La forest is clearly dependent on the emission redshift zem of the QSO itself. This is shown not only by the larger zem QSOs having larger mean density, but more importantly, we have found, at a rather high confidence level, that at the same values of zabs, QSOs with larger zem possess greater number of La absorption lines.(2) If this result can be confirmed with an even larger sample, it will pose a serious diffioulty for the current "intervening hypothesis" or the origin of the La forest.