标题： 星系团表面亮度分布和结构参数对于福纳克斯和人马座矮椭球星系中的球状星团 显示英文标题

标题： Surface Brightness Profiles and Structural Parameters for Globular Clusters in the Fornax and Sagittarius Dwarf Spheroidal Galaxies

摘要： 我们给出了Fornax矮椭球星系中所有五个球状星团的径向表面亮度剖面，以及Sagittarius矮椭球星体星系中四个现存成员的剖面。这些剖面来自档案中的哈勃空间望远镜观测数据，并使用了我们在之前研究LMC和SMC星团时所采用的技术（分别为astro-ph/0209031和astro-ph/0209046），只是做了一些小的修改。从表面亮度剖面中，我们确定了每个星团的结构参数，包括核心半径以及光度和质量估计。我们还提供了这些星团其他参数的文献测量简要总结，包括它们的年龄、金属量和距离。我们的核心半径测量结果与之前低分辨率研究的结果基本一致，尽管对于几个星团，我们的新值有显著不同。Fornax星团5的剖面似乎无法很好地用King型模型拟合，我们认为它是一个核心坍缩后的候选者。我们检查了两个矮星系系统中星团核心半径的分布，并将其与古老LMC星团的核心半径分布进行比较。这三个分布在一个测量误差和小样本量的范围内相匹配。我们讨论了这一结果在我们之前强调的麦哲伦云星团半径-年龄趋势背景下的意义。 显示英文摘要

摘要： We present radial surface brightness profiles for all five globular clusters in the Fornax dwarf spheroidal galaxy, and for the four present members of the Sagittarius dwarf spheroidal galaxy. These profiles are derived from archival Hubble Space Telescope observations, and have been calculated using the same techniques with which we measured profiles in our previous studies of LMC and SMC clusters (astro-ph/0209031 and astro-ph/0209046 respectively), apart from some small modifications. From the surface brightness profiles, we have determined structural parameters for each cluster, including core radii and luminosity and mass estimates. We also provide a brief summary of literature measurements of other parameters for these clusters, including their ages, metallicities and distances. Our core radius measurements are mostly in good agreement with those from previous lower resolution studies, although for several clusters our new values are significantly different. The profile for Fornax cluster 5 does not appear to be well fit by a King-type model and we suggest that it is a post core-collapse candidate. We examine the distribution of cluster core radii in each of the two dwarf galaxy systems, and compare these with the distribution of core radii for old LMC clusters. The three distributions match within the limits of measurement errors and the small sample sizes. We discuss the implications of this in the context of the radius-age trend we have previously highlighted for the Magellanic Cloud clusters.