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标题：Yet another UFO in the X-ray spectrum of a high- z lensed QSO
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作者：M. Dadina ; C. Vignali ; M. Cappi 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2018
卷号：610
DOI：10.1051/0004-6361/201732406
语种：English
出版社：EDP Sciences
摘要：Aim.Ultra-fast outflows (UFO) appear to be common in local active galactic nuclei (AGN) and may be powerful enough (Ėkin≥ 1% ofLbol) to effectively quench the star formation in their host galaxies. To test feedback models based on AGN outflows, it is mandatory to investigate UFOs near the peak of AGN activity, that is, at high-zwhere only a few studies are available to date.Methods.UFOs produce Fe resonant absorption lines measured above ≈7 keV. The most critical problem in detecting such features in distant objects is the difficulty in obtaining X-ray data with sufficient signal-to-noise. We therefore selected a distant QSO that gravitational lensing made bright enough for these purposes, thez= 2.64 QSO MG J0414+0534, and observed it withXMM-Newtonfor ≈78 ks.Results.The X-ray spectrum of MG J0414+0534 is complex and shows signatures of cold absorption (NH≈ 4 × 1022cm−2) and of the presence of an iron emission line (E≈ 6.4 keV,EW= 95 ± 53 eV) consistent with it originating in the cold absorber. Our main result, however, is the robust detection (more than 5σ) of an absorption line atEint≈ 9.2 keV (Eobs≈ 2.5 keV observer frame). If interpreted as due to FeXXVI, it implies gas outflowing atvout≈ 0.3c. To our knowledge, this is the first detection of an UFO in a radio-loud quasar atz≥ 1.5. We estimated that the UFO mechanical output isĖkin≈ 2.5Lbolwithṗout∕ṗrad≈ 17 indicating that it is capable of installing significant feedback between the super-massive black hole and the bulge of the host galaxy. We argue that this also suggests a magnetic driving origin of the UFO.
关键词：Key wordsengalaxies: high-redshiftquasars: individual: MG J0414+0534X-rays: individuals: MG J0414+0534