The COS CGM Compendium. I. Survey Design and Initial Results
The COS CGM Compendium. I. Survey Design and Initial Results
复制标题
COS CGM 纲要。
DOI：
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发表时间：
2018
影响因子：
4.9
通讯作者：
K. Cooksey
中科院分区：
文献类型：
--
作者：
N. Lehner;Christopher B. Wotta;J. Howk;J. O’Meara;B. Oppenheimer;K. Cooksey
我们提出了一个中性氢选择的吸收线调查的气体与H i柱密度在使用宇宙起源光谱仪的哈勃太空望远镜。我们的主要目标是确定这些吸收剂的金属丰度分布。我们的样品由224个吸收剂组成，根据它们的H i吸收强度来选择。在这里，我们讨论我们的调查和直接的实证结果的属性。我们发现单和双离子化的金属物种，和H i通常具有相似的速度分布，这意味着它们探测气体在相同或相似的环境。离子比率（例如，I，I）表明这些吸收器中的气体大部分被电离，并且电离条件在整个采样范围内相当可比。H i的多普勒参数意味着平均K，与被光电离的气体一致。Mg ii柱密度在任何给定的情况下跨越2个数量级，表明金属丰度范围很广（从太阳到<1/100太阳）。在的范围内，有一个差距，在对应的气体与太阳能金属量的10%，一致的差距在以前确定的双峰金属量分布在这个列密度制度的差距。在我们的样品中，不到3%的吸收剂没有显示出可检测的金属吸收，这意味着真正的原始气体是罕见的。我们发现[Fe ii/Mg ii]，并且由于α增强可以影响这个比率，所以尘埃贫化是非常温和的。
We present a neutral hydrogen-selected absorption-line survey of gas with H i column densities at using the Cosmic Origins Spectrograph on the Hubble Space Telescope. Our main aim is to determine the metallicity distribution of these absorbers. Our sample consists of 224 absorbers selected on the basis of their H i absorption strength. Here we discuss the properties of our survey and the immediate empirical results. We find singly and doubly ionized metal species, and H i typically have similar velocity profiles, implying they probe gas in the same or similar environments. The ionic ratios (e.g., / , / ) indicate that the gas in these absorbers is largely ionized, and the ionization conditions are quite comparable across the sampled range. The Doppler parameters of the H i imply K on average, consistent with the gas being photoionized. The Mg ii column densities span >2 orders of magnitude at any given , indicating a wide range of metallicities (from solar to <1/100 solar). In the range of , there is a gap in the distribution corresponding to gas with ∼10% solar metallicity, consistent with the gap seen in the previously identified bimodal metallicity distribution in this column density regime. Less than 3% of the absorbers in our sample show no detectable metal absorption, implying that truly pristine gas at is uncommon. We find [Fe ii/Mg ii] , and since α-enhancement can affect this ratio, dust depletion is extremely mild.
DOI：
10.1086/511749
发表时间：
2006-12
期刊：
The Astrophysical Journal
影响因子：
--
作者：
N. Lehner;B. Savage;P. Richter;K. Sembach;T. Tripp;B. P. W. U. O. N. Dame;U. Wisconsin;U. Bonn;Space Telescope Science Institute;U. O. Massachusetts
通讯作者：
N. Lehner;B. Savage;P. Richter;K. Sembach;T. Tripp;B. P. W. U. O. N. Dame;U. Wisconsin;U. Bonn;Space Telescope Science Institute;U. O. Massachusetts
影响因子：
4.8
作者：
Bielby, R.;Crighton, N. H. M.;Cantalupo, S.
通讯作者：
Cantalupo, S.