Spectroscopy of Massive Stars in the Double Cluster h/chi Persei

英仙座双星团中大质量恒星的光谱

• 批准号: 248134216
• 负责人: Professor Dr. Ulrich Heber
• 金额: --
• 依托单位: Dr. Remeis-Sternwarte Bamberg - Astronomisches Institut -
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/248134216?language=en
• 关键词: Spectroscopy; Massive; Stars; Double; Cluster

Massive stars are main drivers of the evolution of galaxies because of their energy and momentum input into the interstellar medium through stellar winds and supernovae, and they are important sites of nucleosynthesis.The development of a detailed understanding of their inner structure and evolution is of utmost importance for wide fields of astrophysics. Among many others, evolution models of massive stars provide the basis for the interpretation of stellar populations in star clusters and galaxies. They describe the structure of supernova progenitors and allow chemical yields to be predicted. And, they are the starting point for explaining exotic phenomena such as neutron stars, stellar black holes and some types of gamma-ray bursts.Enormous progress has been made in the modelling of massive star evolution by accounting for the effects of rotation. There is a growing body of evidence that rotation together with mass loss are the physical key ingredients shaping the evolution of massive stars throughout cosmic history. The current models make detailed predictions on the surface properties (stellar parameters and chemical abundances) of massive stars that need to be compared to detailed observations for verification of the assumptions made in the models.A survey of the massive star population in the Galactic double cluster h and chi Persei at high spectralresolution and very high signal-to-noise ratio will be undertaken in order to derive tight observationalconstraints on stellar evolution models. The homogeneous sample will cover all evolutionary stages from the main sequence over the giant to the supergiant stage in a well-defined environment of unique age andmetallicity, comprising slow and fast rotators. Use of sophisticated non-LTE modelling and a novel analysismethodology will provide stellar parameters and chemical abundances at unprecedented accuracy andprecision. Surface abundances of the light elements (He, C, N, O) will in particular be used to verify therecently challenged concept of rotational mixing based on a sample of minimised observational bias.We ask for travel money in order to conduct the observing run at Calar Alto Observatory, for which five nights of observing time have been granted with the Echelle spectrograph CAFE on the 2.2m telescope.

大质量恒星是星系演化的主要驱动力，因为它们的能量和动量通过恒星风和超新星输入到星际介质中，它们是核合成的重要场所。对其内部结构和演化的详细了解的发展对天体物理学的广泛领域至关重要。在许多其他理论中，大质量恒星的演化模型为解释星团和星系中的恒星群提供了基础。它们描述了超新星祖先的结构，并使化学产量得以预测。而且，它们是解释奇异现象的起点，如中子星、恒星黑洞和某些类型的伽马射线暴。通过考虑旋转的影响，在大质量恒星演化的建模方面取得了巨大的进展。越来越多的证据表明，在整个宇宙历史中，旋转和质量损失是塑造大质量恒星演化的物理关键因素。目前的模型对大质量恒星的表面特性（恒星参数和化学丰度）做出了详细的预测，这些预测需要与详细的观测结果进行比较，以验证模型中的假设。为了得到恒星演化模型的严格观测约束，我们将在高光谱分辨率和高信噪比下对英仙座双星团h和chi中的大质量恒星群进行调查。均匀的样品将涵盖从主层序到巨星到超巨星的所有演化阶段，在一个明确定义的独特年龄和金属丰度的环境中，包括慢速和快速旋转体。使用复杂的非lte建模和新颖的分析方法将以前所未有的准确性和精度提供恒星参数和化学丰度。轻元素（He， C， N， O）的表面丰度将特别用于验证最近受到挑战的旋转混合概念，该概念基于最小观测偏差的样本。我们要求旅费，以便在Calar Alto天文台进行观测，在2.2米望远镜上的梯队光谱仪CAFE已经获得了五个晚上的观测时间。