Systematically Measuring Ultra-diffuse Galaxies (SMUDGes). I. Survey Description and First Results in the Coma Galaxy Cluster and Environs
Systematically Measuring Ultra-diffuse Galaxies (SMUDGes). I. Survey Description and First Results in the Coma Galaxy Cluster and Environs
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DOI：
10.3847/1538-4365/aaefe9
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发表时间：
2018-11
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影响因子：
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通讯作者：
D. Zaritsky;R. Donnerstein;A. Dey;J. Kadowaki;Huanian 年 Zhang 张华;A. Karunakaran;D. Mart'inez-Delgado;Mubdi Rahman;K. Spekkens
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作者：
D. Zaritsky;R. Donnerstein;A. Dey;J. Kadowaki;Huanian 年 Zhang 张华;A. Karunakaran;D. Mart'inez-Delgado;Mubdi Rahman;K. Spekkens
我们提供了一个均匀的星表，包含了后发座星系团周围290平方度范围内的275个大的（有效半径为1.5.″3）超漫射星系（UDG）候选者。该目录来自我们对Legacy Surveys数据的自动后处理，Legacy Surveys是一个覆盖14，000平方度河外天空的三波段成像调查。我们描述了一个管道，确定UDG，并提供其基本参数。在这些大型UDG中，该调查与先前发表的后发座星团中部地区的UDG调查一样完整。我们得出的结论是，我们的大多数探测都大致在后发座星系团的距离上，这意味着有效半径≥2.5 kpc，并且我们的样本包含大量DF 44的类似物，其中有效半径超过4 kpc，无论是在星系团内部还是在周围的领域。我们的UDG的g-z颜色跨越了很大的范围，这表明即使是大的UDG也可能反映了一系列的形成历史。大多数的UDG是一致的低恒星质量类似物的红色序列星系，但我们发现红色和蓝色的UDG候选人在后发座星系团附近和相对过剩的蓝色UDG候选人在低密度的环境和领域。我们对完整的遗留调查数据的最终处理将产生最大，最均匀的大型UDG样本。
We present a homogeneous catalog of 275 large (effective radius ≳5.″3) ultra-diffuse galaxy (UDG) candidates lying within an ≈290 square degree region surrounding the Coma Cluster. The catalog results from our automated postprocessing of data from the Legacy Surveys, a three-band imaging survey covering 14,000 square degrees of the extragalactic sky. We describe a pipeline that identifies UDGs and provides their basic parameters. The survey is as complete in these large UDGs as previously published UDG surveys of the central region of the Coma Cluster. We conclude that the majority of our detections are at roughly the distance of the Coma Cluster, implying effective radii ≥2.5 kpc, and that our sample contains a significant number of analogs of DF44, where the effective radius exceeds 4 kpc, both within the cluster and in the surrounding field. The g − z color of our UDGs spans a large range, suggesting that even large UDGs may reflect a range of formation histories. A majority of the UDGs are consistent with being lower stellar mass analogs of red sequence galaxies, but we find both red and blue UDG candidates in the vicinity of the Coma Cluster and a relative overabundance of blue UDG candidates in the lower-density environments and the field. Our eventual processing of the full Legacy Surveys data will produce the largest, most homogeneous sample of large UDGs.