An Extended Scheme for Fitting X-Ray Data with Accretion Disk Spectra in the Strong Gravity Regime
An Extended Scheme for Fitting X-Ray Data with Accretion Disk Spectra in the Strong Gravity Regime
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DOI：
10.1086/421115
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发表时间：
2004-03
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影响因子：
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通讯作者：
M. Dovčiak;V. Karas;T. Yaqoob;T. Yaqoob
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作者：
M. Dovčiak;V. Karas;T. Yaqoob;T. Yaqoob
吸积黑洞被认为会发射x射线，然后在发射区域附近介导强引力的信息。本文报道了一组用于分析黑洞吸积盘x射线谱的XSPEC程序。新的计算工具大大扩展了目前可用的拟合程序的能力，包括强引力的影响，并允许人们系统地探索比以前可能的更多模型参数的约束（例如，黑洞角动量）。此外，不假设圆盘本征发射率的轴对称，尽管它可以被施加以加快计算速度。新的程序也可以作为一个独立的和灵活的代码使用，具有处理强重力条件下的时间分辨光谱的能力。我们使用新的代码分析了xmm -牛顿2001长时间运动中Seyfert 1星系MCG -6-30-15的平均x射线光谱。与以往的研究结果一致，我们得到了圆盘内的径向线本征发射率定律（不是简单的幂律）和黑洞角动量的近最大值与宽Fe - K线轮廓的良好拟合。然而，对于黑洞角动量的小值也可以得到同样好的拟合。开发该代码的目的是允许对相对论效应进行精确建模。虽然我们发现目前的数据不能很好地约束黑洞/吸积盘系统的参数，但代码允许在给定的来源或情况下，详细调查数据的哪些特征应该集中在未来的研究中，以实现唯一隔离这类系统参数的目标。
Accreting black holes are believed to emit X-rays, which then mediate information about strong gravity in the vicinity of the emission region. We report on a set of new routines for the XSPEC package for analyzing X-ray spectra of black-hole accretion disks. The new computational tool significantly extends the capabilities of the currently available fitting procedures that include the effects of strong gravity and allows one to systematically explore the constraints on more model parameters than previously possible (e.g., black-hole angular momentum). Moreover, axial symmetry of the disk intrinsic emissivity is not assumed, although it can be imposed to speed up the computations. The new routines can be used also as a stand-alone and flexible code with the capability of handling time-resolved spectra in the regime of strong gravity. We have used the new code to analyze the mean X-ray spectrum from the long XMM-Newton 2001 campaign of the Seyfert 1 galaxy MCG -6-30-15. Consistent with previous findings, we obtained a good fit to the broad Fe K line profile for a radial line intrinsic emissivity law in the disk that is not a simple power law, and for near maximal value of black hole angular momentum. However, equally good fits can be obtained also for small values of the black hole angular momentum. The code has been developed with the aim of allowing precise modeling of relativistic effects. Although we find that current data cannot constrain the parameters of black-hole/accretion disk system well, the code allows, for a given source or situation, detailed investigations of what features of the data future studies should be focused on in order to achieve the goal of uniquely isolating the parameters of such systems.