发表机构
Institute of Astronomy and Astrophysics, Academia Sinica; Hakodate Campus, Hokkaido University of Education; Calle 134A No. 148A 21 San Pedro de Tibabuyes, Suba - Bogotá, Colombia（中央研究院天文及天文物理研究所; 函馆校区 北海道教育大学; 无明确机构名称）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在激波振荡模型中加入康普顿散射改进分析，模拟Sgr A*耀斑的射电与X射线延迟，结果与观测吻合，揭示延迟源于声波传播，为黑洞辐射机制提供新解释。
AI 中文摘要
我们对超大质量黑洞人马座A*（Sgr A*）的射电耀斑与X射线耀斑之间的时间延迟进行了改进分析，在我们先前的激波振荡模型中加入了康普顿散射（Compton scattering）。我们的模拟预测，X射线与射电耀斑之间的延迟时间为1-4小时，334 GHz与4.5 μm、2-8 keV耀斑之间的延迟时间为20-40分钟和0.5-1小时，22-43 GHz射电与350 GHz射电耀斑之间的延迟时间为7-20分钟和0.5-1小时，这与近期观测结果吻合良好。射电同步辐射与X射线轫致辐射之间的延迟时间被解释为声波从事件视界附近的中心核传播至振荡激波位置的传播时间。此外，不同射电波长间观测到的延迟时间对应于声波在频率依赖的有效半径R_eff(ν)之间的传播时间，其中频率ν处的光学厚度τ_ν(R)在吸积盘表面等于1。X射线辐射和低频射电辐射的峰值晚于高频射电辐射，该延迟源于同步辐射产生的声学扰动在事件视界附近达到峰值后向外膨胀；反之，当上游激波产生的声波向事件视界传播时则会出现反向延迟，该解释预测的延迟时间与模拟得到的数值结果定性匹配。
英文摘要
We present an improved analysis of the time delays between radio and X-ray flares from the supermassive black hole Sagittarius A* (Sgr A*), extending our previous shock oscillation model by incorporating Compton scattering. Our simulations predict delay times of 1-4 h between X-ray and radio flares, 20-40 min and 0.5-1 h between 334 GHz and 4.5 $μ$m and 2-8 keV flares, and 7-20 min and 0.5-1 h between 22-43 GHz and 350 GHz radio flares, respectively, in good agreement with recent observations. The delay time between the radio emissions (synchrotron) and X-ray emissions (bremsstrahlung) is interpreted as the transit time for sound waves traveling from the central core near the event horizon to the location of the oscillating shock. Additionally, the delay time observed between different radio wavelengths corresponds to the transit time of sound waves moving between the frequency-dependent effective radii $R_{\rm eff}(ν)$, where the optical thickness $τ_ν(R)$ at frequency $ν$ equals one on the surface of the accretion disc. The X-ray emission and the radio emission at lower frequencies peak later than the radio emission at higher frequencies. This delay occurs because the acoustic perturbations created by synchrotron emission peak near the event horizon and then expand outward. Conversely, an inverse delay happens when the acoustic waves generated by the upstream shock wave travel toward the event horizon. The predicted delay times from this interpretation qualitatively match the numerical results obtained in simulations.
Comments12 pages, 8 figures, Accepted for publication in MNRAS
