Clues about the star formation history of the M31 disc from WFPC2 photometry
Clues about the star formation history of the M31 disc from WFPC2 photometry
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DOI：
10.1046/j.1365-8711.2002.05088.x
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发表时间：
2001-11
影响因子：
4.8
通讯作者：
B. Williams
中科院分区：
文献类型：
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作者：
B. Williams
在过去的几年里，哈勃太空望远镜(HST)已经在M31圆盘上获取了许多不同区域的宽带图像。我已经从HST数据档案中获得了27个这样的场，以便生成包含在盘的这些区域内的恒星种群的彩色星等图(CMD)。我试图使用理论恒星演化模型结合统计工具来复制这些CMD，以确定最符合观测结果的恒星形成历史。在任何给定的区域内，消光值的范围很大，使得数据很难准确地复制；然而，我设法找到了大致复制数据的恒星形成历史。这些统计确定的恒星形成历史表明，就像银河系的圆盘一样，M31的圆盘中几乎没有古老的贫金属星。历史还表明，在过去的∼1 Gyr期间，该盘的恒星形成率作为一个整体一直很低。
Over the past several years, the Hubble Space Telescope (HST) has acquired many broadband images of various regions in the M31 disc. I have obtained 27 such fields from the HST data archive in order to produce colour-magnitude diagrams (CMDs) of the stellar populations contained within these areas of the disc. I have attempted to reproduce these CMDs using theoretical stellar evolution models in conjunction with statistical tools for determining the star formation history that best fits the observations. The wide range of extinction values within any given field makes the data difficult to reproduce accurately; nevertheless, I have managed to find star formation histories that roughly reproduce the data. These statistically determined star formation histories reveal that, like the disc of the Galaxy, the disc of M31 contains very few old metal-poor stars. The histories also suggest that the star formation rate of the disc as a whole has been low over the past ∼ 1 Gyr.