arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2306.08054astro-ph.HEgr-qc
收藏

克尔黑洞引发的潮汐瓦解事件的轨道倾角分布

Distribution of orbital inclinations for tidal disruption events by Kerr black holes

Tamanjyot Singh, Michael Kesden

AI总结:

本研究针对克尔黑洞潮汐瓦解事件,考虑倾角保持与各向同性两种损失锥填充极限,计算了轨道倾角分布、穿透因子分布、总TDE率及最大黑洞质量,揭示了黑洞自旋与倾角相关效应对TDE的影响规律。

摘要:

描述自旋超大质量黑洞(SMBH)时空的Kerr度规是轴对称的,这意味着恒星接近SMBH所沿的近抛物线测地线取决于轨道角动量相对于SMBH自旋的倾角$\iota$。该倾角既会影响决定恒星是否会被潮汐瓦解的测地线偏差,也会影响潮汐碎片能否逃过事件视界的直接俘获,从而产生可观测的潮汐瓦解事件(TDE)。稳态TDE率是恒星被散射进入由这些自旋和倾角相关效应决定的损失锥的速率。由于这种损失锥再填充的各向异性存在高度不确定性,我们考虑了两种极端极限:恒星倾角保持不变(IP,倾角保持)和恒星倾角各向同性化(ISO,各向同性)。我们计算了这两种极限下的倾角分布,发现在IP极限下存在顺行偏差,这是因为直接俘获存在强烈的逆行偏差。然而,在ISO极限下,对于中等质量的SMBH,当空损失锥抑制了俘获效应,并让测地线偏差较弱的逆行偏差占据主导时,会出现逆行偏差。部分空的损失锥会导致穿透因子$\beta$的分布比满损失锥下的分布更陡峭,这种效应在ISO极限下更为显著。我们还计算了这两种极限下的总TDE率以及潮汐瓦解的最大SMBH质量$M_{\rm \bullet, max}$。在IP极限下,我们发现TDE率存在高度依赖自旋的俘获截止值,且对于最大自旋的SMBH,$M_{\rm \bullet, max} \approx 10^{8.45} M_\odot$。在ISO极限下,我们发现在中等SMBH质量下,TDE率存在强烈的自旋相关增强,在$M_\bullet \approx 10^{7.5} M_\odot$以上存在弱自旋相关的俘获截止值,且对于最大自旋的SMBH,$M_{\rm \bullet, max} \approx 10^{7.95} M_\odot$。

英文摘要:

The Kerr metric that describes the spacetime of a spinning supermassive black hole (SMBH) is axisymmetric, implying that the nearly parabolic geodesics on which stars approach the SMBH depend on the inclination angle $ι$ of the orbital angular momentum with respect to the SMBH spin. This inclination affects both the geodesic deviation that determines whether a star is tidally disrupted and whether the tidal debris survives direct capture by the event horizon to produce an observable tidal disruption event (TDE). The steady-state TDE rate is the rate at which stars are scattered into the loss cone determined by these spin- and inclination-dependent effects. As the anisotropy of this loss-cone refilling is highly uncertain, we consider the two extreme limits in which stellar inclination is preserved (IP) or isotropized (ISO). We calculate the inclination distribution in these two limits and find a prograde bias in the IP limit because of the strong retrograde bias for direct capture. However, we find a retrograde bias in the ISO limit for intermediate SMBH masses when the empty loss cone suppresses capture and allows the weaker retrograde bias of geodesic deviation to dominate. Partially empty loss cones lead to steeper distributions of the penetration factor $β$ than for a full loss cone, with this effect even more pronounced in the ISO limit. We also calculate the total TDE rates and maximum SMBH mass $M_{\rm \bullet, max}$ for tidal disruption in these two limits. In the IP limit, we find a highly spin-dependent capture cutoff in the TDE rate and $M_{\rm \bullet, max} \approx 10^{8.45} M_\odot$ for maximal SMBH spin. In the ISO limit, we find a strong spin-dependent enhancement in the TDE rate at intermediate SMBH masses, a weakly spin-dependent capture cutoff above $M_\bullet \approx 10^{7.5} M_\odot$, and $M_{\rm \bullet, max} \approx 10^{7.95} M_\odot$ for maximal SMBH spin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑