A multiwavelength study of multiple spectral component jets in AGN: testing the IC/CMB model for the large-scale-jet X-ray emission
A multiwavelength study of multiple spectral component jets in AGN: testing the IC/CMB model for the large-scale-jet X-ray emission
复制标题
AGN 中多光谱分量射流的多波长研究：测试大规模射流 X 射线发射的 IC/CMB 模型
DOI：
10.1093/mnras/stac3081
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发表时间：
2022
影响因子：
4.8
通讯作者：
Roychowdhury, Agniva
中科院分区：
文献类型：
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作者：
Breiding, Peter;Meyer, Eileen T.;Georganopoulos, Markos;Reddy, Karthik;Kollmann, Kassidy E.;Roychowdhury, Agniva
ChandraX射线天文台已经发现了超过150个分辨率的、由活动星系核承载的kpc级X射线喷流。这些喷流中有很大一部分的X射线光谱要么通量太高，要么太硬，与无线电-光学同步加速器光谱的高能量扩展不一致，我们将其确定为多光谱分量（MSC）X射线喷流。X射线起源的一个主要假设是宇宙微波背景的逆康普顿散射，由产生射电-光学同步加速器光谱的相同电子群产生（称为IC/CMB模型）。在这项工作中，我们测试的IC/CMB模型在45河外X射线喷流使用观测从费米大面积望远镜寻找预期的高水平的伽马射线发射，利用观测从阿塔卡马大型毫米/亚毫米阵列（阿尔马）和哈勃太空望远镜（HST）时，可能的最佳约束预测的伽马射线通量。包括这个和以前的工作，我们现在发现IC/CMB模型被排除在总共24/45 MSC X射线喷流，由于其过度预测所观察到的MeV到GeV的伽马射线通量。我们提出了额外的证据，对IC/CMB模型，包括相对X射线到无线电相对论波束在这些来源，和无线电和X射线光谱指数之间的一般不匹配。最后，我们提出了上限的基础上的费米上限，这表明这些射流是在最温和的相对论性的所有射流的大规模整体流量洛伦兹因子。
Over ∼150 resolved, kpc-scale X-ray jets hosted by active galactic nuclei have been discovered with theChandraX-ray Observatory. A significant fraction of these jets have an X-ray spectrum either too high in flux or too hard to be consistent with the high-energy extension of the radio-to-optical synchrotron spectrum, a subtype we identify as Multiple Spectral Component (MSC) X-ray jets. A leading hypothesis for the origin of the X-rays is the inverse-Compton scattering of the cosmic microwave background by the same electron population producing the radio-to-optical synchrotron spectrum (known as the IC/CMB model). In this work, we test the IC/CMB model in 45 extragalactic X-ray jets using observations from theFermiLarge Area Telescope to look for the expected high level of gamma-ray emission, utilizing observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and theHubble Space Telescope(HST) when possible to best constrain the predicted gamma-ray flux. Including this and previous works, we now find the IC/CMB model to be ruled out in a total of 24/45 MSC X-ray jets due to its over-prediction for the observed MeV-to-GeV gamma-ray flux. We present additional evidence against the IC/CMB model, including the relative X-ray-to-radio relativistic beaming in these sources, and the general mismatch between radio and X-ray spectral indexes. Finally, we present upper limits on the large-scale bulk-flow Lorentz factors for all jets based on the Fermi upper limits, which suggest that these jets are at most mildly relativistic.