تقرير
Merger rate density of Population III binary black holes below, above, and in the pair-instability mass gap
| العنوان: | Merger rate density of Population III binary black holes below, above, and in the pair-instability mass gap |
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| المؤلفون: | Tanikawa, Ataru, Susa, Hajime, Yoshida, Takashi, Trani, Alessandro A., Kinugawa, Tomoya |
| المصدر: | The Astrophysical Journal, 910:30 (31pp), 2021 March |
| سنة النشر: | 2020 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | We present the merger rate density of Population (Pop.) III binary black holes (BHs) by means of a widely-used binary population synthesis code BSE with extensions to very massive and extreme metal-poor stars. We consider not only low-mass BHs (lBHs: $5-50 M_\odot$) but also high-mass BHs (hBHs: $130-200 M_\odot$), where lBHs and hBHs are below and above the pair-instability mass gap ($50-130 M_\odot$), respectively. Pop. III BH-BHs can be categorized into three subpopulations: BH-BHs without hBHs (hBH0s: $m_{\rm tot} \lesssim 100 M_\odot$), with one hBH (hBH1s: $m_{\rm tot} \sim 130-260 M_\odot$), and with two hBHs (hBH2s: $m_{\rm tot} \sim 270-400 M_\odot$), where $m_{\rm tot}$ is the total mass of a BH-BH. Their merger rate densities at the current universe are $\sim 0.1$ yr$^{-1}$ Gpc$^{-3}$ for hBH0s, and $\sim 0.01$ yr$^{-1}$ Gpc$^{-3}$ for the sum of hBH1s and hBH2s, provided that the mass density of Pop. III stars is $\sim 10^{13} M_\odot$ Gpc$^{-3}$. These rates are modestly insensitive to initial conditions and single star models. The hBH1 and hBH2 mergers can dominate BH-BHs with hBHs discovered in near future. They have low effective spins $\lesssim 0.2$ in the current universe. The number ratio of the hBH2s to the hBH1s is high, $\gtrsim 0.1$. We also find BHs in the mass gap (up to $\sim 85 M_\odot$) merge. These merger rates can be reduced to nearly zero if Pop. III binaries are always wide ($\gtrsim 100 R_\odot$), and if Pop. III stars always enter into chemically homogeneous evolution. The presence of close Pop. III binaries ($\sim 10 R_\odot$) are crucial for avoiding the worst scenario. Comment: 38 pages, 33 figures, accepted for publication in ApJ |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.3847/1538-4357/abe40d |
| URL الوصول: | http://arxiv.org/abs/2008.01890 |
| رقم الأكسشن: | edsarx.2008.01890 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.3847/1538-4357/abe40d |
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