Merging binary black holes formed through double-core evolution

作者：Ying Qin, Rui-Chong Hu, G. Meynet, Y. Z. Wang, Jin-Ping Zhu, Hanfeng Song, Xinwen Shu, Shichao Wu · 发表于：Astronomy and Astrophysics · 年份：2023 · DOI：10.1051/0004-6361/202244712 · 被引用次数：17 · 研究领域：Pulsars and Gravitational Waves Research、Astrophysical Phenomena and Observations、Gamma-ray bursts and supernovae

Context. To date, various formation channels of merging events have been heavily explored with the detection of nearly 100 double black hole (BH) merger events reported by the LIGO-Virgo-KAGRA (LVK) Collaboration. In this paper, we systematically investigate an alternative formation scenario: binary BHs (BBHs) formed through double helium stars (hereafter, “double-core evolution channel”). In this scenario, two helium stars (He-rich stars) could be the outcome of the classical isolated binary evolution scenario with and without the common envelope (CE) phase (i.e., CE channel and stable mass transfer channel) or, alternatively, of massive close binaries evolving chemically homogeneously (i.e., CHE channel). Aims. We study the properties (i.e., the chirp masses and the effective spins) of BBHs formed through the double-core evolution and investigate the impact of different efficiencies of angular momentum transport within massive He-rich stars on double-core evolution. Methods. We performed detailed stellar structure and binary evolution calculations that take into account internal rotation and mass loss of He-rich stars as well as tidal interactions in binaries. We systematically studied the parameter space of initial binary He-rich stars, including the initial mass and metallicity of He-rich stars as well as initial orbital periods. Apart from direct core collapse with mass and angular momentum conserved, we also follow the framework in Batta & Ramirez-Ruiz (2019, ArXiv ...