First star survivors as metal-rich halo stars that experienced supernova explosions in binary systems
First star survivors as metal-rich halo stars that experienced supernova explosions in binary systems
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DOI：
10.1093/pasj/psab024
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发表时间：
2021-03
影响因子：
2.3
通讯作者：
T. Suda;T. Saitoh;Y. Moritani;T. Matsuno;T. Shigeyama
中科院分区：
文献类型：
--
作者：
T. Suda;T. Saitoh;Y. Moritani;T. Matsuno;T. Shigeyama
寻找宇宙中第一批由无金属气体形成的恒星是天文学的关键问题之一，因为它涉及许多领域，例如恒星和星系的形成、宇宙的演化、元素的起源等。目前尚不清楚是否可以在当前宇宙中找到无金属的第一颗恒星。这些第一批恒星被认为存在于我们银河系光环中金属极其贫乏的恒星中。在这里，我们提出了一个新的场景，用于描述一直存活到今天的低质量第一颗恒星以及我们银河系中可观测的对应恒星的形成。双星系统中的第一批恒星由大质量和低质量恒星组成，通过恒星演化模型、超新星喷射物与低质量伴星碰撞的模拟以及与观测数据的比较来进行检查。这些第一批恒星幸存者将在我们的银河系中被观测为富含金属的晕恒星。我们可能已经在观测数据库中确定了一颗候选恒星，其中可以获得元素丰度和运动学数据。我们的模型还解释了文献中存在的几颗太阳金属星的存在，这些恒星的空间速度相当于晕群。所提出的情景需要在早期宇宙中建立一个新的恒星形成通道，并且是对已知贫金属恒星起源的补充情景。
The search for the first stars formed from metal-free gas in the universe is one of the key issues in astronomy because it relates to many fields, such as the formation of stars and galaxies, the evolution of the universe, and the origin of elements. It is not still clear if metal-free first stars can be found in the present universe. These first stars are thought to exist among extremely metal-poor stars in the halo of our Galaxy. Here we propose a new scenario for the formation of low-mass first stars that have survived until today and observational counterparts in our Galaxy. The first stars in binary systems, consisting of massive- and low-mass stars, are examined using stellar evolution models, simulations of supernova ejecta colliding with low-mass companions, and comparisons with observed data. These first star survivors will be observed as metal-rich halo stars in our Galaxy. We may have identified a candidate star in the observational database where elemental abundances and kinematic data are available. Our models also account for the existence in the literature of several solar-metallicity stars that have space velocities equivalent to the halo population. The proposed scenario demands a new channel of star formation in the early universe and is a supplementary scenario for the origin of the known metal-poor stars.