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arXiv 1102.0798astro-ph.GA
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AGN的模拟光谱态和观测预报

Simulated spectral states of AGN and observational predictions

M. A. Sobolewska, A. Siemiginowska, M. Gierlinski

摘要:

活动星系核(AGN)和星系黑洞双星(GBH)代表了两类吸积黑洞。它们都包含一个释放热辐射的吸积盘和一个非热X射线发射日冕。GBH表现出状态跃迁,其光谱状态的特征在于不同的光度水平和光谱能量分布(SED)的形状。如果活动星系核以类似的方式发生跃迁,这种跃迁的特征时间尺度将超过10^5年。因此,观测到单个活动星系核在不同光谱态之间跃迁的概率非常低。本文跟踪了一个GBH(GRO~J1655-40)的光谱演化过程,并在一个大样本活动星系核应该包含不同光谱态的混合源的假设下,将其SED演化模式应用于模拟的活动星系核总体。我们用等对模型模拟GRO J1655-40的X射线谱,然后用黑洞质量标度最佳拟合模型来模拟活动星系核的谱。我们比较了模拟和观测到的活动星系核SED,以确定观测到的1型活动星系核,LINER和NLS 1人口的光谱状态。我们的结论是,明亮的1型活动星系核和NLS 1星系的光谱状态类似于GBH的软光谱状态,而LINER的光谱状态可能对应于GBH的硬光谱状态。我们发现,考虑到在几个数量级的黑洞质量的传播,在所观察到的活动星系核样本,导致X射线响度和单色光度之间的相关性在2500 A,类似于观察中发现的。然而,我们预言,在临界亮度Lcrit ~ 0.01LE附近,相关性改变了它的符号.

英文摘要:

Active galactic nuclei (AGN) and galactic black hole binaries (GBHs) represent two classes of accreting black holes. They both contain an accretion disc emitting a thermal radiation, and a non-thermal X-ray emitting corona. GBHs exhibit state transitions, and their spectral states are characterized by different luminosity levels and shapes of the spectral energy distribution (SED). If AGN transitioned in a similar way, the characteristic timescales of such transitions would exceed ~10^5 years. Thus, the probability to observe an individual AGN transiting between different spectral states is very low. In this paper we follow a spectral evolution of a GBH, GRO~J1655-40, and then apply its SED evolution pattern to a simulated population of AGN under an assumption that a large sample of AGN should contain a mixture of sources in different spectral states. We model the X-ray spectra of GRO J1655-40 with the eqpair model and then scale the best-fitting models with the black hole mass to simulate the AGN spectra. We compare the simulated and observed AGN SEDs to determine the spectral states of observed Type 1 AGN, LINER and NLS1 populations. We conclude that bright Type 1 AGN and NLS1 galaxies are in a spectral state similar to the soft spectral state of GBHs, while the spectral state of LINERs may correspond to the hard spectral state of GBHs. We find that taking into account a spread in the black hole masses over several orders of magnitude, as in the observed AGN samples, leads to a correlation between the X-ray loudness and the monochromatic luminosity at 2500A, similar to that found in observations. We predict however that the correlation changes its sign around a critical luminosity of L_crit ~ 0.01 L_E.

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