Close encounters of tight binary stars with stellar-mass black holes
Close encounters of tight binary stars with stellar-mass black holes
复制标题
紧密双星与恒星质量黑洞的近距离接触
DOI：
10.1093/mnras/stad079
复制
发表时间：
2023
影响因子：
4.8
通讯作者：
de Mink, Selma E.
中科院分区：
文献类型：
--
作者：
Ryu, Taeho;Perna, Rosalba;Pakmor, Ruediger;Ma, Jing-Ze;Farmer, Rob;de Mink, Selma E.
在各种天体物理环境中，如星星团和活动星系核盘中，恒星和致密天体之间预计会有强动力学相互作用。通过一套三维流体动力学模拟，利用动网格程序arepo，我们研究了等质量圆双星星星与单黑洞（BH）近距离碰撞过程中瞬态现象的形成及其性质.恒星在动力学相互作用过程中会被黑洞破坏，自然产生电磁瞬变现象。碰撞参数小于初始二进制的半长轴经常会导致各种瞬态的电磁签名是定性的不同，从普通的中断事件，涉及两个机构。这包括两颗恒星同时或相继的破裂，以及一颗星星的完全破裂伴随着另一颗星星的连续部分破裂。相反，当碰撞参数大于初始双星的半长轴时，双星要么是简单的潮汐扰动，要么是解离成束缚和非束缚的单星（“微山”机制）。双星的分离可以产生一颗逃逸的星星和一颗活动的BH，它们彼此远离。此外，双星的解离可以产生与BH相互作用的双星，也可以产生非相互作用的硬双星;两者都可能是BH高质量和低质量X射线双星的候选者。因此，我们的模拟特别证实，强烈的遭遇可以导致（通常难以形成）BH低质量X射线双星的形成。
Strong dynamical interactions among stars and compact objects are expected in a variety of astrophysical settings, such as star clusters and the disks of active galactic nuclei. Via a suite of three-dimensional hydrodynamics simulations using the moving-mesh codearepo, we investigate the formation of transient phenomena and their properties in close encounters between anorequal-mass circular binary star and singleblack hole (BH). Stars can be disrupted by the BH during dynamical interactions, naturally producing electromagnetic transient phenomena. Encounters with impact parameters smaller than the semimajor axis of the initial binary frequently lead to a variety of transients whose electromagnetic signatures are qualitatively different from those of ordinary disruption events involving just two bodies. These include the simultaneous or successive disruptions of both stars and one full disruption of one star accompanied by successive partial disruptions of the other star. On the contrary, when the impact parameter is larger than the semimajor axis of the initial binary, the binary is either simply tidally perturbed or dissociated into bound and unbound single stars (‘micro-Hills’ mechanism). The dissociation ofbinaries can produce a runaway star and an active BH moving away from one another. Also, the binary dissociation can either produce an interacting binary with the BH, or a non-interacting, hard binary; both could be candidates of BH high- and low-mass X-ray binaries. Hence, our simulations especially confirm that strong encounters can lead to the formation of the (generally difficult to form) BH low-mass X-ray binaries.