A METHOD FOR LOCALIZING ENERGY DISSIPATION IN BLAZARS USING FERMI VARIABILITY
A METHOD FOR LOCALIZING ENERGY DISSIPATION IN BLAZARS USING FERMI VARIABILITY
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DOI：
10.1088/2041-8205/758/1/l15
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发表时间：
2012-09
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影响因子：
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通讯作者：
Amanda Dotson;M. Georganopoulos;D. Kazanas;E. Perlman
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文献类型：
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作者：
Amanda Dotson;M. Georganopoulos;D. Kazanas;E. Perlman
费米探测到的耀变体γ射线发射点与超大质量黑洞的距离是一个活跃的争论问题。在这里，我们提出了一种方法来测试，如果强大的耀变体的GeV的排放产生在亚秒差距尺度的宽线区（BLR）或更远的秒差距尺度的分子环面（MT）的环境。如果GeV辐射发生在BLR内，则产生γ射线的BLR紫外（UV）种子光子的逆康普顿（IC）散射发生在克莱因-西名机制的开始。这使得电子冷却时间变得几乎与能量无关，并且γ射线发射的变化几乎是消色差的。另一方面，如果γ射线发射在更远的秒差距尺度MT中产生，则产生γ射线的红外（IR）MT种子光子的IC散射发生在汤姆逊区，导致能量依赖的电子冷却时间，表现为更高费米能量的更快冷却时间。我们展示了这些特点，并讨论了我们的方法的适用性和局限性。
The distance of a Fermi-detected blazar γ-ray emission site from a supermassive black hole is a matter of active debate. Here we present a method for testing if the GeV emission of powerful blazars is produced within the subparsec-scale broad-line region (BLR) or farther out in the parsec-scale molecular torus (MT) environment. If the GeV emission takes place within the BLR, the inverse Compton (IC) scattering of the BLR ultraviolet (UV) seed photons that produces the γ-rays takes place at the onset of the Klein–Nishina regime. This causes the electron cooling time to become practically energy-independent and the variation of the γ-ray emission to be almost achromatic. If, on the other hand, the γ-ray emission is produced farther out in the parsec-scale MT, the IC scattering of the infrared (IR) MT seed photons that produces the γ-rays takes place in the Thomson regime, resulting in energy-dependent electron cooling times, manifested as faster cooling times for higher Fermi energies. We demonstrate these characteristics and discuss the applicability and limitations of our method.