论文标题
两个高红移h $ _2 $ - 含量GRB-DLAS，120815A和121024A的身体状况
Physical conditions in two high-redshift H$_2$-bearing GRB-DLAs, 120815A and 121024A
论文作者
论文摘要
伽马射线爆发（GRB）余气为研究高红移星系星系星际星系的星际介质（ISM）提供了独特的机会。 GRB-DLAS（阻尼Lyman-$α$吸收器）包含大型中性氢柱密度N（H I），并针对GRB余辉观察。大部分GRB-DLAS显示出存在分子氢（H $ _2 $）的存在，这是恒星形成的指标。因此，重要的是研究那些具有H $ _2 $行的GRB-DLA，以破译和了解其身体状况。 GRB-DLAS 121024A和120815A分别位于Redshift 2.30和2.36，是两个如此重要的H $ _2 $ bugreation grb-dlas。除了h $ _2 $，这两个GRB-DLA还显示了许多金属线。在这项工作中，我们在GRB-DLAS 121024A和120815A自搭配时进行了一项有关H $ _2 $线以及这些金属线的详细数值研究。我们将光谱合成代码多云用于这项研究。这种建模有助于我们确定产生这种线条的潜在物理条件，从而比以前的任何其他研究更详细地了解这两个GRB-DLA。我们发现，这两个H $ _2 $的DLA的氢密度为$ \ geq $ 60 cm $^{ - 3} $。此外，我们的研究据说，这两个GRB-DLA的线性大小为$ \ leq 17.7 $ PC，而平均气温在云厚度上平均为$ \ leq $ 140 k。
The gamma-ray burst (GRB) afterglows provide an unique opportunity to study the interstellar medium (ISM) of star-forming galaxies at high-redshift. The GRB-DLAs (damped Lyman-$α$ absorbers) contain a large neutral hydrogen column density, N(H I), and are observed against the GRB afterglow. A large fraction of GRB-DLAs show presence of molecular hydrogen (H$_2$) which is an indicator of star-formation. Hence it is important to study those GRB-DLAs which have H$_2$ lines to decipher and understand their physical conditions. The GRB-DLAs 121024A and 120815A, situated at redshift 2.30 and 2.36 respectively, are two such important H$_2$-bearing GRB-DLAs. Besides H$_2$, these two GRB-DLAs also show many metal lines. In this work we have carried out a detail numerical study on the H$_2$ lines, as well as on those metal lines, in GRB-DLAs 121024A and 120815A self-consistently. We use the spectral synthesis code CLOUDY for this study. This modeling helps us to determine the underlying physical conditions which give rise such lines and hence to understand these two GRB-DLAs in much more detail than any other previous investigation. We find that the hydrogen densities for these two H$_2$-bearing DLAs are $\geq$ 60 cm$^{-3}$. Moreover our study infers that the linear sizes are $\leq 17.7$ pc for these two GRB-DLAs, and the mean gas temperatures averaged over the cloud thickness, are $\leq$ 140 K.
