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arXiv 1208.4103astro-ph.GA
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GALFA-HI紧凑型云目录

The GALFA-HI Compact Cloud Catalog

Destry R. Saul, J. E. G. Peek, J. Grcevich, M. E. Putman, K. A. Douglas, E. J. Korpela, S. Stanimirovic, C. Heiles, S. J. Gibson, M. Lee, A. Begum, A. R. H. Bro… 展开作者

Destry R. Saul, J. E. G. Peek, J. Grcevich, M. E. Putman, K. A. Douglas, E. J. Korpela, S. Stanimirovic, C. Heiles, S. J. Gibson, M. Lee, A. Begum, A. R. H. Brown, B. Burkhart, E. T. Hamden, N. M. Pingel, S. Tonnesen

摘要:

我们提出了一个目录1964年孤立的,紧凑的中性氢云从银河阿雷西博L波段馈电阵列调查数据发布一(GALFA-HI DR 1)。通过定制的机器视觉算法识别云,该算法利用高斯核的差来搜索小于20“的云。这些云的速度通常在|VLSR| = 20-400 km/s之间,线宽为2.5 ~ 35 km/s,云柱密度为1 ~ 35 x 10^18 cm^-2。在这个星表中,云的距离可能涵盖几个数量级,因此质量范围可能从银河系圆盘内的云小于太阳质量到麦哲伦流尖端的HVC大于10^4太阳质量。为了寻找趋势,我们根据位置,速度和线宽将目录分为五个群体:高速云(HVC);星系候选人;冷低速云(LVC);第三银河象限的温暖,低正速度云;和剩余的温暖LVC。所观察到的HVC被发现与以前确定的HVC复合物。我们并没有像一些模型预测的那样,在高速下观察到大量的孤立云。我们看到了不同的历史,在低速检测人口的云与银河系盘和一组云,不共转。

英文摘要:

We present a catalog of 1964 isolated, compact neutral hydrogen clouds from the Galactic Arecibo L-Band Feed Array Survey Data Release One (GALFA-HI DR1). The clouds were identified by a custom machine-vision algorithm utilizing Difference of Gaussian kernels to search for clouds smaller than 20'. The clouds have velocities typically between |VLSR| = 20-400 km/s, linewidths of 2.5-35 km/s, and column densities ranging from 1 - 35 x 10^18 cm^-2. The distances to the clouds in this catalog may cover several orders of magnitude, so the masses may range from less than a Solar mass for clouds within the Galactic disc, to greater than 10^4 Solar Masses for HVCs at the tip of the Magellanic Stream. To search for trends, we separate the catalog into five populations based on position, velocity, and linewidth: high velocity clouds (HVCs); galaxy candidates; cold low velocity clouds (LVCs); warm, low positive-velocity clouds in the third Galactic Quadrant; and the remaining warm LVCs. The observed HVCs are found to be associated with previously-identified HVC complexes. We do not observe a large population of isolated clouds at high velocities as some models predict. We see evidence for distinct histories at low velocities in detecting populations of clouds corotating with the Galactic disc and a set of clouds that is not corotating.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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