Black Holes in Binary Systems: Observational Appearances
Black Holes in Binary Systems: Observational Appearances
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DOI：
10.1017/s007418090010035x
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
N. Shakura;R. Sunyaev
中科院分区：
文献类型：
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作者：
N. Shakura;R. Sunyaev
吸积物质的角动量向外转移可以导致在黑洞周围形成一个圆盘。圆盘的结构和辐射光谱主要取决于物质在圆盘外部边界流入圆盘的速率。对角动量输运机制(与磁场和湍流有关)效率的依赖性较弱。如果M={10^-9}-3倍{10^-8}{M_\odot}/yr，则黑洞周围的圆盘是一个很强的X射线辐射源，能量密度为hv~1-10keV，光度为L~1037-1038erg S−1。如果吸积物质的通量减少，辐射的有效温度和光度将下降。同时，当(\点M>；{10^{-9}}{M_\OOT}y{r^{-1}})时，盘的光学光度超过太阳盘。对黑洞光学光度的主要贡献是由于该部分X射线和紫外线能量的重新辐射，这些能量最初产生于盘的中心高温区域，然后被低温外部区域吸收。这类天体的光辐射光谱必须被宽广的发射复合和共振线饱和。变率与双星系统中黑洞和气流的运动特征有关，也可能与日食有关。在定义明确的条件下，硬辐射可以蒸发气体。这可以抵消流入磁盘的物质，并导致吸积的自动调节。
The outward transfer of angular momentum of accreting matter can lead to the formation of a disk around the black hole. The structure and radiation spectrum of the disk depends, in the main, on the rate of matter inflow \(\dot M\) into the disk at its external boundary. Dependence on the efficiency of mechanisms of angular momentum transport (connected with the magnetic field and turbulence) is weaker. If \(\dot M = {10^{ - 9}} - 3 \times {10^{ - 8}} {M_ \odot }/yr\), the disk around the black hole is a powerful source of X-radiation with hv ~ 1–10 keV and luminosity L ~ 1037–1038 erg s−1. If the flux of the accreting matter decreases, the effective temperature of radiation and the luminosity will drop. At the same time when \(\dot M >{10^{ - 9}}{M_ \odot }y{r^{ - 1}}\), the optical luminosity of the disk exceeds the solar one. The main contribution to the optical luminosity of the black hole is due to the re-radiation of that part of the X-ray and ultraviolet energy which is initially produced in the central high temperature regions of the disk and which is then absorbed by the low temperature outer regions. The optical radiation spectrum of such objects must be saturated by the broad emission recombination and resonance lines. Variability is connected with the character of the motion of the black hole and the gas flow in binary systems and possibly with eclipses. For well defined conditions, the hard radiation can evaporate the gas. This can counteract the matter inflow into the disk and lead to autoregulation of the accretion.