文章基本信息

标题：Constraining X-ray emission of a magnetically arrested disk by radio-loud AGNs with an extreme-ultraviolet deficit
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作者：Shuang-Liang Li ; Minhua Zhou ; Minfeng Gu 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2022
卷号：663
页码：1-5
DOI：10.1051/0004-6361/202244105
语种：English
出版社：EDP Sciences
摘要：Aims. Active galactic nuclei (AGNs) with an extreme-ultraviolet (EUV) deficit are suggested to be powered by a magnetically arrested disk (MAD) surrounding the black hole, where the slope of EUV spectra (αEUV) is found to possess a clearly positive relationship with the jet efficiency. In this work, we investigate the properties of X-ray emission in AGNs with an EUV deficit for the first time. Methods. We constructed a sample of 15 objects with an EUV deficit to analyze their X-ray emission. The X-ray luminosity in 13 objects was recently processed by us, while the other two sources were gathered from archival data. Results. It is found that the average X-ray flux of AGNs with an EUV deficit are 4.5 times larger than that of radio-quiet AGNs (RQAGNs), while the slope of the relationship between the optical-UV luminosity (LUV) and the X-ray luminosity (LX) is found to be similar with that of RQAGNs. For comparison, the average X-ray flux of radio-loud AGNs (RLAGNs) without an EUV deficit is about 2–3 times larger than that of RQAGNs. A strong positive correlation between αEUV and radio loudness (RUV) is also reported. However, there is no strong relationship between LX and the radio luminosity (LR). Conclusions. Both the excess of X-ray emission of RLAGNs with an EUV deficit and the strong αEUV−RUV relationship can be qualitatively explained with the MAD scenario, which can help one to constrain the theoretical model of MAD.
关键词：accretion;accretion disks;black hole physics;magnetohydrodynamics (MHD);galaxies: active;X-rays: galaxies