Chemically Peculiar Hot Subdwarfs

化学性质特殊的热亚矮星

• 批准号: 2279889
• 金额: --
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2279889
• 关键词: Chemically; Peculiar; Hot; Subdwarfs

Summary: Hot subdwarfs represent a rare but relatively-long-lived class of star, now clearly identified by GAIA as a distinct class in the Hertzsprung-Russell diagram. The majority have hydrogen-rich surfaces and can be accounted for as core-helium burning stars which lost most of their surface layers in a close binary-star interaction. About 10 - 20 per cent have helium rich surfaces, and must come from other evolution channels. We are carrying out a spectroscopic survey of these stars with SALT and also with LAMOST, and are discovering an extraordinary variety of exotic objects, including heavy-metal subdwarfs, runaway stars, extreme population II stars, and new extreme helium stars. The student will take over the day-to-day operation and reduction of the SALT survey data, and will learn techniques of spectral analysis to examine individual stars, in order to contribute to a more comprehensive picture of the late stages of stellar evolution.

摘要：热亚矮星代表了一类罕见但相对寿命较长的恒星，现在盖亚明确地将其识别为赫罗图中的一个独特类别。大多数具有富含氢的表面，可以被解释为核心氦燃烧的恒星，它们在紧密的双星相互作用中失去了大部分表面层。大约 10% - 20% 的表面富含氦气，并且必须来自其他演化通道。我们正在利用 SALT 和 LAMOST 对这些恒星进行光谱调查，并发现了各种各样的奇异天体，包括重金属亚矮星、失控恒星、极端星族 II 恒星和新的极端氦星。学生将负责SALT巡天数据的日常操作和缩减，并将学习光谱分析技术来检查单个恒星，以便为更全面地了解恒星演化的后期阶段做出贡献。