论文标题
旋转轨道未对准的起源:微黄骨V4641 SGR
Origin of Spin-Orbit Misalignments: The Microblazar V4641 Sgr
论文作者
论文摘要
在已知的微QuaSar中,V4641 SGR在相对论射流轴与二元轨道角动量之间的未对准角上具有最严重的下限(> 52°)。假设喷气孔和黑洞旋转轴一致,我们试图用Natal Kick模型来解释这种极端自旋轨道未对准的起源,从而使排列的二进制系统被赋予新生儿黑洞的超新星踢而错过。模型输入是踢速度分布,我们将其定制为V4641 SGR,以及立即/后/后 - Supernova二进制系统参数。使用二进制恒星演化模型的网格,我们确定了supernova后的配置,这些配置能够与今天的V4641 SGR保持一致,并通过使用标准处方来获得公共包膜演化的标准处方。使用这些潜在的祖细胞系统参数集作为输入,我们发现出生的脚踢来解释V4641 SGR旋转轨道未对准的起源。因此,我们得出的结论是,对于V4641 SGR而言,涉及标准共同包膜阶段的进化途径极不可能。另一种解释是,射流轴无法可靠地追踪黑洞旋转轴。我们的结果引起了人们对从二元种群综合模型收集的紧凑型物体合并统计数据的担忧,这些统计依赖于未经验证的处方来进行共同的信封进化和出生踢。我们还挑战了通常调用的自旋轨道对准假设,以测量黑洞自旋幅度。
Of the known microquasars, V4641 Sgr boasts the most severe lower limit (> 52°) on the misalignment angle between the relativistic jet axis and the binary orbital angular momentum. Assuming the jet and black hole spin axes coincide, we attempt to explain the origin of this extreme spin-orbit misalignment with a natal kick model, whereby an aligned binary system becomes misaligned by a supernova kick imparted to the newborn black hole. The model inputs are the kick velocity distribution, which we measure customized to V4641 Sgr, and the immediate pre/post-supernova binary system parameters. Using a grid of binary stellar evolution models, we determine post-supernova configurations that evolve to become consistent with V4641 Sgr today and obtain the corresponding pre-supernova configurations by using standard prescriptions for common envelope evolution. Using each of these potential progenitor system parameter sets as inputs, we find that a natal kick struggles to explain the origin of the V4641 Sgr spin-orbit misalignment. Consequently, we conclude that evolutionary pathways involving a standard common envelope phase followed by a supernova kick are highly unlikely for V4641 Sgr. An alternative interpretation is that the jet axis does not reliably trace the black hole spin axis. Our results raise concerns about compact object merger statistics gleaned from binary population synthesis models, which rely on unverified prescriptions for common envelope evolution and natal kicks. We also challenge the spin-orbit alignment assumption routinely invoked to measure black hole spin magnitudes.