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천문우주과학 연구동향

천문우주과학과 관련된 국내외 상위 학술논문 및 특허 정보를 제공해 드립니다.

거대 성단 내의 다양한 연대의 항성의 확산을 배제

The exclusion of a significant range of ages in a massive star cluster
  • 작성자 : KASI
  • 작성일 : 2014-12-22
  • 조회수 : 2994
  • 저자Chengyuan Li, Richard de Grijs et.al
  • Absract


    Stars spend most of their lifetimes on the main sequence in the Hertzsprung–Russell diagram. The extended main-sequence turnoff regions—containing stars leaving the main sequence after having spent all of the hydrogen in their cores—found in massive (more than a few tens of thousands of solar masses), intermediate-age (about one to three billion years old) star clusters are usually interpreted as evidence of internal age spreads of more than 300 million years, although young clusters are thought to quickly lose any remaining star-forming fuel following a period of rapid gas expulsion on timescales of order 10 years. Here we report, on the basis of a combination of high-resolution imaging observations and theoretical modelling, that the stars beyond themain sequence in the twobillion-year-old cluster NGC1651, characterized by a mass of about 1.73105 solar masses3, can be explained only by a single-age stellar population, even though the cluster has a clearly extended mainsequence turn-off region.Themost plausible explanationfor the existence of such extended regions invokes a population of rapidly rotating stars, although the secondary effects of the prolonged stellar lifetimes associated with such a stellar population mixture are as yet poorly understood. From preliminary analysis of previously obtained data, we find that similar morphologies are apparent in the Hertzsprung–Russell diagrams of at least five additional intermediateage star clusters, suggesting that an extended main-sequence turn-off region does not necessarily imply the presence of a significant internal age dispersion.


  • 게재정보NATURE(2014.12.17)에 게재된 논문임
  • 첨부파일
  • 원 문http://www.nature.com/nature/journal/v516/n7531/full/nature13969.html
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