ULTRA-COMPACT DWARFS IN THE COMA CLUSTER
ULTRA-COMPACT DWARFS IN THE COMA CLUSTER
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DOI：
10.1088/0004-637x/737/2/86
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
K. Chiboucas;R. Tully;R. Marzke;S. Phillipps;J. Price;E. Peng;N. Trentham;D. Carter;D. Hammer-D.-Hamme
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文献类型：
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作者：
K. Chiboucas;R. Tully;R. Marzke;S. Phillipps;J. Price;E. Peng;N. Trentham;D. Carter;D. Hammer-D.-Hamme
作为哈勃太空望远镜/高级巡天照相机（HST/ACS）后发座星系宝库巡天的一部分，我们在动态演化的大规模后发座星系团的致密核心中进行了超紧凑矮星系（UCD）的光谱搜索。UCD候选者最初是根据ACS图像中的颜色、大小、分辨率以及天炉座和室女座UCD的已知属性来选择的。Keck/Low-Resolution Imaging Spectrometer的后续光谱确认了27个候选彗星，成功率>60%，目标天体亮度大于MR =-12。另外14个候选者也可能被证明是昏迷成员，但低信噪比光谱阻止了明确的结论。对昏迷UCD的属性和分布的调查发现，这些对象与在其他环境中发现的UCD非常相似。后发座UCD倾向于聚集在星系团核心的巨型星系周围，并且具有与宿主星系相关的颜色/金属丰度。与属性和分布类似的后发座星系团球状星团人口，我们发现强有力的支持星星集群起源的后发座UCD的大多数。然而，一些UCD似乎有恒星人口或结构特性，使它们与后发座星系团中发现的旧星星群人口不同，这可能表明UCD可能通过多种形成渠道形成。
We have undertaken a spectroscopic search for ultra-compact dwarf galaxies (UCDs) in the dense core of the dynamically evolved, massive Coma cluster as part of the Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) Coma Cluster Treasury Survey. UCD candidates were initially chosen based on color, magnitude, degree of resolution within the ACS images, and the known properties of Fornax and Virgo UCDs. Follow-up spectroscopy with Keck/Low-Resolution Imaging Spectrometer confirmed 27 candidates as members of the Coma cluster, a success rate >60% for targeted objects brighter than MR = −12. Another 14 candidates may also prove to be Coma members, but low signal-to-noise spectra prevent definitive conclusions. An investigation of the properties and distribution of the Coma UCDs finds these objects to be very similar to UCDs discovered in other environments. The Coma UCDs tend to be clustered around giant galaxies in the cluster core and have colors/metallicity that correlate with the host galaxy. With properties and a distribution similar to that of the Coma cluster globular cluster population, we find strong support for a star cluster origin for the majority of the Coma UCDs. However, a few UCDs appear to have stellar population or structural properties which differentiate them from the old star cluster populations found in the Coma cluster, perhaps indicating that UCDs may form through multiple formation channels.