论文标题
候选电磁对应于二进制黑洞合并引力波事件S190521G
Candidate Electromagnetic Counterpart to the Binary Black Hole Merger Gravitational Wave Event S190521g
论文作者
论文摘要
我们报告了（候选）二进制黑洞（BBH）合并的第一个合理的光电磁（EM）对应物。由Zwicky瞬态设施（ZTF）检测到，EM耀斑与有效银河核（AGN）的积聚磁盘中对BBH合并的期望一致，并且由于此源的内在可变性，因此不太可能（$ <o（0.01 \％$））。缺乏颜色演化意味着它不是超新星，而是强烈暗示恒温冲击。排除或限制为$ <o（0.1 \％$），将其他假阳性事件（例如微透镜或潮汐破坏事件）排除在外。如果耀斑与S190521G相关联，我们会发现以下值的值：总质量$ m _ {\ rm bbh} \ sim 100 m _ {\ odot} $，kick velocity $ v_k \ sim 200 \， 60^{\ circ} $在具有长宽比$ h/a \ sim 0.01 $的磁盘中（即，磁盘高度$ h $ at radius $ a $）和气体密度$ρ\ sim 10^{ - 10} \，{\ rm g}合并可能发生在磁盘迁移陷阱（$ a \ sim 700 \，r_ {g} $; $ r_g \ equiv g m _ {\ rm smbh} / c^2 $，其中$ m _ {\ rm smbh} $是Agn Superssupsive Blacksive Blackholes的质量。参数的组合意味着对于S190521G中至少一个黑洞的一个显着自旋。我们的光谱法的时机阻止了由于偏心耀斑而导致的宽线不对称的有用限制。由于$ \ sim 1.6 \，{\ rm yr} \，（m _ {\ rm smbh}/10^{8} {8} m _ {\ odot}）\，（m _ {\ rm smbh}/10^{3} r _ {3/r _ r _} = 3，我们会预测该来源中的重复爆发。
We report the first plausible optical electromagnetic (EM) counterpart to a (candidate) binary black hole (BBH) merger. Detected by the Zwicky Transient Facility (ZTF), the EM flare is consistent with expectations for a kicked BBH merger in the accretion disk of an active galactic nucleus (AGN), and is unlikely ($<O(0.01\%$)) due to intrinsic variability of this source. The lack of color evolution implies that it is not a supernovae and instead is strongly suggestive of a constant temperature shock. Other false-positive events, such as microlensing or a tidal disruption event, are ruled out or constrained to be $<O(0.1\%$). If the flare is associated with S190521g, we find plausible values of: total mass $ M_{\rm BBH} \sim 100 M_{\odot}$, kick velocity $v_k \sim 200\, {\rm km}\, {\rm s}^{-1}$ at $θ\sim 60^{\circ}$ in a disk with aspect ratio $H/a \sim 0.01$ (i.e., disk height $H$ at radius $a$) and gas density $ρ\sim 10^{-10}\, {\rm g}\, {\rm cm}^{-3}$. The merger could have occurred at a disk migration trap ($a \sim 700\, r_{g}$; $r_g \equiv G M_{\rm SMBH} / c^2$, where $M_{\rm SMBH}$ is the mass of the AGN supermassive black hole). The combination of parameters implies a significant spin for at least one of the black holes in S190521g. The timing of our spectroscopy prevents useful constraints on broad-line asymmetry due to an off-center flare. We predict a repeat flare in this source due to a re-encountering with the disk in $\sim 1.6\, {\rm yr}\, (M_{\rm SMBH}/10^{8}M_{\odot})\, (a/10^{3}r_{g})^{3/2}$.
