The local stellar population of nova regions in the Large Magellanic Cloud
The local stellar population of nova regions in the Large Magellanic Cloud
复制标题
大麦哲伦星云中新星区域的局部恒星群
DOI：
10.1051/0004-6361:20020742
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发表时间：
2002
影响因子：
6.5
通讯作者：
G. Anupama
中科院分区：
文献类型：
--
作者：
A. Subramaniam;G. Anupama
本研究的目的是通过研究当地的，预计的，恒星人口，以确定和了解大麦哲伦星云（LMC）中的新星的父母人口。根据OGLE II巡天和星星星团星表中新星附近恒星和星星星团的光度数据，研究了新星周围局部环境的星星形成历史。新星区域周围几角分范围内恒星群的年龄是使用V与（VI）色星等图的等时线拟合来估计的。利用主序星和红巨星的光度函数比较了不同演化状态下恒星的比例。估计了15颗新星的年龄、密度和光度函数。除慢新星LMC 1948外，所有区域的中间星族年龄上限均为4 Gyr。这些区域中的星星形成被发现在4-2.0 Gyr前开始，大部分区域在3.2 Gyr开始形成星星。这一星星形成事件持续了1.6-0.8 Gyr。快速新星和中快速新星的基本星群的星星形成历史表明，它们的母星星群相似，年龄可能在3.2-1.0 Gyr之间。这与银河系激变变星的理论年龄估计值非常吻合。慢新星周围的区域显示恒星的年龄范围在1-10 Gyr之间，其中很大一部分年龄超过4 Gyr。这表明，祖先可能属于一个更古老的人口，符合的想法，祖先的慢新星属于更古老的人口。
This study aims at identifying and understanding the parent population of novae in the Large Magellanic Cloud (LMC) by studying the local, projected, stellar population. The star formation history of the local environment around novae is studied based on photometric data of stars and star clusters in the nova neighbourhood, available in the OGLE II survey and star cluster catalogues. The age of the stellar population within a few arcmin around nova regions are estimated using isochrone fits to the V vs. (V I) colour-magnitude diagrams. The fraction of stars in various evolutionary states are compared using luminosity functions of the main-sequence stars and the red giant stars. The age, density and luminosity function of the stellar population are estimated around 15 novae. The upper limit of the age of the intermediate stellar population is found to be 4 Gyr in all the regions, excepting the region around the slow nova LMC 1948. Star formation in these regions is found to have started between 4-2.0 Gyr ago, with a majority of the regions starting star formation at 3.2 Gyr. This star formation event lasted upto 1.6-0.8 Gyr. The star formation history of the underlying population of both the fast and moderately fast novae indicate their parent popula- tion to be similar and likely to be in the age range 3.2-1.0 Gyr. This is in good agreement with the theoretical age estimates for Galactic cataclysmic variables. The region around the slow nova shows a stellar population in the age range 1-10 Gyr, with a good fraction older than 4 Gyr. This indicates that the progenitor might belong to an older population, consistent with the idea that the progenitors of slow novae belong to older population.