X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at <i>z</i> = 6.56
X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at <i>z</i> = 6.56
复制标题
<i>z</i> = 6.56 处快速吸积的窄线 Seyfert 1 星系发出的 X 射线
DOI：
10.1051/0004-6361/202244688
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发表时间：
2023
影响因子：
6.5
通讯作者：
Waddell S. G. H.
中科院分区：
文献类型：
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作者：
Wolf J.;Nandra K.;Salvato M.;Buchner J.;Onoue M.;Liu T.;Arcodia R.;Merloni A.;Ciroi S.;Di Mille F.;Burwitz V.;Brusa M.;Ishimoto R.;Kashikawa N.;Matsuoka Y.;Urrutia T.;Waddell S. G. H.
背景X射线发光、盲目选择的活动星系核(AGN)的空间密度通过宇宙时间追踪快速吸积的超大质量黑洞的数量。它被编码在X射线光度函数中，在大爆炸后的第一个10亿年里，由于X射线测量到目前为止缺乏所需的宇宙体积，其亮度端仍然受到很差的限制。随着eROSITA最终赤道深度调查(EFEDS)，这是迄今为止最大的连续和均匀的X射线调查，X射线活动星系核群体研究现在可以扩展到光度红移空间的新区域(L2 − 10 kev>； 1045erg S−1和z>； 6)。目的本研究旨在从eFEDS场中选定的X射线源中识别z>； 5.7处的发光类星体，以便将黑洞吸积的下限限制到重新电离时代。第二个目标是描述这些极端日冕发射体在高红移时的物理性质。方法将eFEDS星表来源与来自DESI遗留成像测量的光学对应物进行交叉匹配，我们确认了利用eROSITA探测到的低重要性，该探测来自斯巴鲁高亮度类星体探测(SHELLQs)，光学上微弱的TZ= 6.56类星体。我们用钱德拉X射线望远镜对震源进行了有针对性的跟踪观测，以确认低意义的eROSITA探测。利用新的近红外光谱，我们推导出了超大质量黑洞的物理性质。最后，我们利用这个探测来推断 6的黑洞吸积密度的下限。结果Chandra观测证实eFEDS源是迄今为止最远的盲X射线探测。相对于类星体静止标架的光学发射，导出的X射线光度很高。该源具有窄的镁II线、低的导出黑洞质量、高的爱丁顿比和陡峭的光子指数，显示出类似于局部窄线塞弗特1星系的性质，后者被认为是由年轻的超大质量黑洞提供动力的。结合先前在场上探测到的高红移类星体，我们证明了具有L2 − 10 kev>； 1045erg S−1的类星体在∼ 6时对超大质量黑洞的吸积起主导作用。
ContextThe space density of X-ray-luminous, blindly selected active galactic nuclei (AGN) traces the population of rapidly accreting super-massive black holes through cosmic time. It is encoded in the X-ray luminosity function, whose bright end remains poorly constrained in the first billion years after the Big Bang as X-ray surveys have thus far lacked the required cosmological volume. With the eROSITA Final Equatorial-Depth Survey (eFEDS), the largest contiguous and homogeneous X-ray survey to date, X-ray AGN population studies can now be extended to new regions of the luminosity–redshift space (L2 − 10 keV> 1045erg s−1andz> 6).AimsThe current study aims at identifying luminous quasars atz> 5.7 among X-ray-selected sources in the eFEDS field in order to place a lower limit on black hole accretion well into the epoch of re-ionisation. A secondary goal is the characterisation of the physical properties of these extreme coronal emitters at high redshifts.MethodsCross-matching eFEDS catalogue sources to optical counterparts from the DESI Legacy Imaging Surveys, we confirm the low significance detection with eROSITA of a previously known, optically faintz= 6.56 quasar from the Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs) survey. We obtained a pointed follow-up observation of the source with theChandraX-ray telescope in order to confirm the low-significance eROSITA detection. Using new near-infrared spectroscopy, we derived the physical properties of the super-massive black hole. Finally, we used this detection to infer a lower limit on the black hole accretion density rate atz> 6.ResultsTheChandraobservation confirms the eFEDS source as the most distant blind X-ray detection to date. The derived X-ray luminosity is high with respect to the rest-frame optical emission of the quasar. With a narrow MgII line, low derived black hole mass, and high Eddington ratio, as well as its steep photon index, the source shows properties that are similar to local narrow-line Seyfert 1 galaxies, which are thought to be powered by young super-massive black holes. In combination with a previous high-redshift quasar detection in the field, we show that quasars withL2 − 10 keV> 1045erg s−1dominate accretion onto super-massive black holes atz∼ 6.