VESTIGE OF THE STAR CLUSTER BURST IN M51
VESTIGE OF THE STAR CLUSTER BURST IN M51
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DOI：
10.1088/0004-637x/709/1/411
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发表时间：
2009-12
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影响因子：
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通讯作者：
N. Hwang;M. Lee
中科院分区：
文献类型：
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作者：
N. Hwang;M. Lee
基于哈勃太空望远镜(HST)的先进巡天相机(ACS)和广角行星相机2号(WFPC2)拍摄的图像数据，我们研究了M51星团的形成。通过比较光度学数据(F336W、F435W、F555W和F814W)和理论人口合成模型，我们利用大约2000个星团的年龄和质量得出了星团的形成率。星团形成率在100-250百万年间显著增加。这一周期与理论模型预期的NGC5194和NGC5195这两个星系的动力学相遇时期大致重合。星团的年龄分布也显示出两个峰值，分别出现在100Myr和250Myr之前。星团质量在10~3~106M☉范围内，质量函数可用指数为2.2 3±0.34的幂函数表示.年龄大于10Myr的星团的质量函数似乎也表现出最陡峭的分布，α≈−为1.50，大约在200Myr之前，接近星系相互作用的预期时期。我们还证实了集群大小与集群质量(最佳拟合斜率为0.16±0.02)和集群年龄(0.14±0.03)之间的相关性。
We present a study of the star cluster formation in M51 based on the image data taken with Advanced Camera for Surveys (ACS) and Wide Field Planetary Camera 2 (WFPC2) of Hubble Space Telescope (HST). We have derived the star cluster formation rate using the ages and masses of about 2000 star clusters estimated by comparing photometric data (F336W, F435W, F555W, and F814W) with theoretical population synthesis models. The star cluster formation rate increased significantly during the period of 100–250 Myr ago. This period roughly coincides with the epoch of dynamical encounters of two galaxies, NGC 5194 and NGC 5195, expected by theoretical models. The age distribution of the star clusters also shows two peaks at about 100 Myr and 250 Myr ago. The star cluster mass ranges from 103 to 106 M☉ and the mass function can be represented by a power law with an index ranging from α = −2.23 ± 0.34 for t 100 Myr. The mass function of star clusters older than 10 Myr also appears to display the steepest distribution with α ≈ −1.50 at around 200 Myr ago, near the expected epoch of the galaxy interaction. We also confirm the correlations of cluster size increasing with cluster mass (with a best-fit slope of 0.16 ± 0.02), and with cluster age (0.14 ± 0.03).