Based on astrometric measurements and spectral analysis from Gaia DR3, two quiescent black hole (BH) binaries, Gaia BH1 and BH2, have been identified. Their origins remain controversial, particularly for Gaia BH1. By considering a rapidly rotating (ω/ω _crit = 0.8) and strongly magnetized (B ₀ = 5000 G) merger product, we find that, at typical Galactic metallicity, the merger product can undergo efficient chemically homogeneous evolution. This results in the merger product having a significantly smaller radius during its evolution compared to that of a normally evolving massive star. Under the condition that the initial triple stability is satisfied, we use the Multiple Stellar Evolution code and the MESA code to identify an initial hierarchical triple that can evolve into Gaia BH1. It initially consists of three stars with masses of 9.03 M _⊙, 3.12 M _⊙, and 1 M _⊙, with inner and outer orbital periods of 2.21 days and 121.92 days, and inner and outer eccentricities of 0.41 and 0.45, respectively. This triple initially experiences triple evolution dynamics instability (TEDI) followed by Roche lobe overflow (RLOF). During RLOF, the inner orbit shrinks, and tidal effects gradually suppress the TEDI. Eventually, the inner binary undergoes a merger through contact (or collision). Finally, using models of rapidly rotating and strongly magnetic stars, along with standard core-collapse supernova (SN) or failed supernova (FSN) models, we find that a postmerger binary (PMB) consisting of an 12.11 M _⊙ merger product and a 1 M _⊙ companion star (originally an outer tertiary) can avoid RLOF. After an SN or FSN with a low ejected mass of ∼0.22 M _⊙ and a low kick velocity ( 46−33+25kms−1 or 9−8+16kms−1 ), the PMB can form Gaia BH1 in the Galactic disk.

中文翻译：

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Gaia BH1 的可能形成情景：三重系统中的内部二进制合并


根据 Gaia DR3 的天体测量和光谱分析，已经确定了两个静止黑洞 （BH） 双星，Gaia BH1 和 BH2。它们的起源仍然存在争议，尤其是对于 Gaia BH1。通过考虑快速旋转 （ω/ω_crit = 0.8） 和强磁化 （B₀ = 5000 G） 合并产物，我们发现，在典型的银河系金属丰度下，合并产物可以经历有效的化学均匀演化。这导致合并产物在其演化过程中的半径比正常演化的大质量恒星的半径小得多。在满足初始三重稳定性的情况下，我们使用 Multiple Stellar Evolution 代码和 MESA 代码来识别一个可以演化成 Gaia BH1 的初始分层三重。它最初由三颗质量分别为 9.03 M_⊙、3.12 M_⊙ 和 1 M_⊙ 的恒星组成，内外轨道周期分别为 2.21 天和 121.92 天，内外偏心率分别为 0.41 和 0.45。这个三重体最初经历三重进化动力学不稳定性 （TEDI），然后是罗氏叶溢出 （RLOF）。在 RLOF 期间，内眼眶收缩，潮汐效应逐渐抑制 TEDI。最终，内部二进制通过接触（或碰撞）经历合并。最后，使用快速旋转和强磁星的模型，以及标准的核心坍缩超新星 （SN） 或失败的超新星 （FSN） 模型，我们发现由 12.11 M_⊙ 合并产物和 1 M_⊙ 伴星（最初是外第三级星）组成的合并后双星 （PMB） 可以避免 RLOF。在射出质量数低至 ∼0 的 SN 或 FSN 之后。22 M_⊙ 和低踢速（46-33+25kms-1 或 9-8+16kms-1），PMB 可以在银河系盘中形成 Gaia BH1。