The Star Formation History of the Starburst Region NGC 2363 and its Surroundings
The Star Formation History of the Starburst Region NGC 2363 and its Surroundings
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星暴区NGC 2363及其周围的恒星形成历史
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
R. Doyon
中科院分区：
文献类型：
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作者：
L. Drissen;J. Roy;C. Robert;D. Devost;R. Doyon
我们给出了哈勃太空望远镜的光学图像和紫外光谱，以及高表面亮度巨型H II区NGC 2363(NGC 2366-I)及其周围的地面近红外图像。研究了矮不规则星系NGC2366南端的大质量恒星含量，重点研究了Wolf-Rayet和红超巨星，并尝试重建了该星系西南端最近一次大质量恒星形成的时间序列。NGC 2366-II的年龄为10 Myr，NGC 2363-B的年龄为2.5-5 Myr，NGC 2363-A的年龄小于1 Myr。特别是，我们发现NGC2363最大质量的超星系团A仍然埋藏在尘埃中；根据相关云团的光蒸发侵蚀或“清洁”时间尺度，我们推断其年龄为∼106年或更短。我们得出的结论是，NGC2366-I和2366-II是一个很好的多阶段恒星爆发的例子，其特征年龄在400pC的线性尺度上从10Myr下降到不到1Myr。恒星的年龄序列和气体运动学表明，这些强大的恒星形成事件是由一颗经过的小卫星触发的。
We present Hubble Space Telescope optical images and UV spectra, as well as ground-based near-infrared images of the high surface-brightness giant H II region NGC 2363 (NGC 2366-I) and its surroundings. The massive star content of the southern end of the dwarf irregular galaxy NGC 2366 is investigated, with an emphasis on Wolf-Rayet and red supergiant stars, and we attempt the reconstruction of the time sequence of the most recent episode of massive star formation at the southwestern tip of the galaxy. The ages of the clusters are, respectively, 10 Myr for NGC 2366-II, 2.5–5 Myr for NGC 2363-B, and less than 1 Myr for NGC 2363-A. In particular, we show that the most massive supercluster A of NGC 2363 is still embedded in dust; from the photoevaporative erosion or "cleaning" timescale of the associated cloud, we infer its age to be ∼106 yr or less. We conclude that the star-forming complex NGC 2366-I and 2366-II is a good example of a multiple stage starburst with a characteristic age decreasing from 10 Myr to less than 1 Myr over a linear scale of 400 pc. The age sequence of the stars and the gas kinematics suggest that these powerful star formation episodes are being triggered by a small passing-by satellite.