arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2006.07407astro-ph.GAastro-ph.HE
收藏

AGN吸积盘中双星黑洞的演化:盘-双星相互作用和引力波发射

Evolution of binary black holes in AGN accretion discs: Disc-binary interaction and gravitational wave emission

W. Ishibashi, M. Gröbner

摘要:

双黑洞合并是LIGO/Virgo探测到的引力波事件的主要来源。嵌入活动星系核(AGN)吸积盘中的二元黑洞是这种GW事件的可能候选者。结合盘-双星相互作用的演化方程和GW螺旋,我们发展了一个理想化的分析模型,用于分析活动星系核吸积盘中BBH的轨道演化。我们调查耦合的“光盘+GW”驱动的BBHs从光盘驱动的制度过渡到GW驱动的制度,在小的分离轨道分离的演变。在这个演化通道中,BBH合并被加速的轨道衰变和轨道偏心率增长的组合在光盘为主的政权。我们提供了一个量化的合并时间尺度$τ_\text{merger}$,并分析其依赖于吸积盘和二进制轨道参数。通过计算的GW频率的函数的轨道偏心率的演变,我们预测,大多数双星活动星系核盘应具有显着的剩余偏心率($e \sim 0.01-0.1$),潜在的LISA检测。我们进一步讨论了这种特殊的BBH在AGN通道的二元演化路径的框架内的潜力和警告。

英文摘要:

Binary black hole (BBH) mergers are the primary sources of gravitational wave (GW) events detected by LIGO/Virgo. Binary black holes embedded in the accretion discs of active galactic nuclei (AGN) are possible candidates for such GW events. We develop an idealised analytic model for the orbital evolution of BBHs in AGN accretion discs by combining the evolution equations of disc-binary interaction and GW inspiral. We investigate the coupled `disc+GW'-driven evolution of BBHs transitioning from the disc-driven regime at large orbital separations into the GW-driven regime at small separations. In this evolution channel, BBH mergers are accelerated by a combination of orbital decay and orbital eccentricity growth in the disc-dominated regime. We provide a quantification of the resulting merger timescale $τ_\text{merger}$, and analyse its dependence on both the accretion disc and binary orbital parameters. By computing the evolution of the orbital eccentricity as a function of the GW frequency, we predict that most binaries in AGN discs should have significant residual eccentricities ($e \sim 0.01-0.1$), potentially detectable by LISA. We further discuss the potentials and caveats of this particular BBH-in-AGN channel in the framework of binary evolutionary paths.

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。

↑