标题： 吸积黑洞光谱中的喷流特征 显示英文标题

标题： Jet Signatures in the Spectra of Accreting Black Holes

摘要： 喷流在活动星系核（AGN）中以射电辐射形式被观测到，并且在X射线双星（XRBs）的低/硬态期间也被观测到，但它们在更高频率下的贡献一直存在不确定性。我们使用广义相对论磁流体动力学（GRMHD）代码HARM来研究XRBs中的喷流动力学。我们使用基于grmonty的广义相对论辐射传输代码计算高能光谱和变化特性。我们发现喷流辐射的以下特征：(i) 在约10^22 Hz以上有一个显著的伽马射线峰值，(ii) 光学/紫外光谱中有一个拐点，光度从L ~ nu^0 变为L ~ nu，随后在更高频率处出现另一个拐点，此时光谱大致回到L ~ nu^0，以及(iii) 在约10^15 Hz以下的明显同步辐射峰值表明所有更高能量的辐射都起源于喷流。我们研究了大规模磁场反转期间的变化，在此期间Blandford-Znajek（BZ）喷流被抑制，而重新连接的磁场则发射出一个新的瞬变现象。伽马射线与X射线的比率从BZ喷流中的L_g /L_X > 1 变为瞬变中的L_g /L_X < 1。我们还发现稳态BZ喷流中有短时间尺度（约几毫秒）的X射线和伽马射线变化，我们将这种现象归因于喷流-吸积盘界面不稳定性引起的QPO效应。 显示英文摘要

摘要： Jets are observed as radio emission in active galactic nuclei (AGN) and during the low/hard state in X-ray binaries (XRBs), but their contribution at higher frequencies has been uncertain. We study the dynamics of jets in XRBs using the general-relativistic magnetohydrodynamic (GRMHD) code HARM. We calculate the high-energy spectra and variability properties using a general-relativistic radiative transport code based on grmonty. We find the following signatures of jet emission (i) a significant gamma-ray peak above ~ 10^22 Hz, (ii) a break in the optical/UV spectrum, with a change in luminosity from L ~ nu^0 to L ~ nu, followed by another break at higher frequencies where the spectrum roughly returns to L ~ nu^0 , and (iii) a pronounced synchrotron peak below ~ 10^15 Hz indicates that all higher energy emission originates in the jet. We investigate the variability during a large-scale magnetic field inversion in which the Blandford-Znajek (BZ) jet is quenched and a new transient is launched by the reconnecting field. The ratio of the gamma-rays to X-rays changes from L_g /L_X > 1 in the BZ jet to L_g /L_X < 1 in the transient. We also find short timescale (~ few ms) X-ray and gamma-ray variability in the steady BZ jet, which we attribute to the effects of QPOs resulting from instabilities at the jet-disk interface.