H2, HD, and CO at the edge of 30 Dor in the LMC: The line of sight to Sk-69 246
H2, HD, and CO at the edge of 30 Dor in the LMC: The line of sight to Sk-69 246
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H2、HD 和 CO 位于 LMC 30 Dor 边缘：Sk-69 246 的视线
DOI：
10.1051/0004-6361:20011302
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
K. S. Boer
中科院分区：
文献类型：
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作者：
H. Bluhm;K. S. Boer
Sk-69 246是一颗位于30 Dor北部的wn6恒星，它的引信和IUE观测显示，LMC星际气体至少在3个速度分量中存在。在其中一种组分中，熔断光谱显示分子氢的强吸收，柱密度为$\log N$ （H $_2)=19.6$）。我们研究了这片云的物理条件，它可能位于Sk-69 246周围的Hii区域附近。检测到柱密度分别为${\approx} 13.9$和13.0的HD和CO。N （CO）与N （h2）的比值与银河系中发现的值一致。从h2的旋转能级的占比中，我们得到了72 K的气体温度和1000 a时的辐射场$U\approx3\times 10^{-15}$ erg s -1 cm -3。对于$E(B-V)\la0.1$来说，分数丰度$f=2N({\rm H}_2)/[N({\rm \ion{H}{i}})+2N({\rm H}_2)]\approx0.07$相当高。
Fuse and IUE observations of Sk-69 246, a WN 6 star to the north of 30 Dor, reveal the existence of LMC interstellar gas in at least 3 velocity components. In one of these components Fuse spectra show strong absorption by molecular hydrogen with a column density of $\log N$(H$_2)=19.6$. We investigate the physical conditions in this cloud, which is probably located near the Hii region surrounding Sk-69 246. HD and CO with column densities of ${\approx} 13.9$ and 13.0, respectively, are detected. The N (CO)-to- N (H 2 ) ratio is consistent with values found in the Galaxy. From the population of the rotational levels of H 2 we derive a gas temperature of 72 K and a radiation field $U\approx3\times 10^{-15}$ erg s -1 cm -3 at 1000 A. The fractional abundance $f=2N({\rm H}_2)/[N({\rm \ion{H}{i}})+2N({\rm H}_2)]\approx0.07$ is rather high for an $E(B-V)\la0.1$.