The XMM Deep survey in the CDFS V. Iron K lines from active galactic nuclei in the distant Universe
S. Falocco, F. J. Carrera, A. Corral, X. Barcons, A. Comastri, R. Gilli, P. Ranalli, C. Vignali, K. Iwasawa, N. Cappelluti, E. Rovilos, I. Georgantopoulos, M. Brusa, F. Vito
X-ray spectroscopy of active galactic nuclei (AGN) offers the opportunity to directly probe the inner regions of the accretion disk. We present the results of our analysis of average AGN XMM-Newton X-ray spectra in the Chandra Deep Field South observation (XMM CDFS). We computed the average spectrum of a sample of 54 AGN with spectroscopic redshifts and signal-to-noise ratio S/N > 15 in the 2-12 keV rest-frame band in at least one EPIC camera. We have taken the effects of combining spectra from sources at different redshifts and both EPIC cameras into account, as well as their spectral resolution; we checked our results using thorough simulations. We explored the Fe line components of distant AGN focusing on the narrow core which arises from regions far from the central engine and on the putative relativistic component (from the accretion disk). The average spectrum shows a highly significant Fe feature. Our model-independent estimates of the equivalent width (EW) suggest a higher EW in a broader range. The line, modelled as an unresolved Gaussian, is significant at 6.8 sigma and has an EW=95 eV (full sample). The current data can be fitted equally well adding a relativistic profile to the narrow component (in the full sample, EW=140 eV and 67 eV respectively for the relativistic and narrow lines). Thanks to the high quality of the XMM CDFS spectra and to the detailed modelling of the continuum and instrumental effects, we have shown that the most distant AGN exhibit a highly significant Fe emission feature. It can be modelled both with narrow and broad lines. We found tantalising evidence for reflection by material both very close and far away from the central engine. The EW of both features are similar to those observed in individual nearby AGN, hence they must be a widespread characteristic of AGN, since otherwise the average values would be smaller than observed.
XMM-牛顿在过去十年(2001-2002年和2008-2009年)的许多时期都观测到了Chandra Deep Field South(CDF-S),总共约为3 M。调查的主要目标是获得质量良好的活动星系核的X射线光谱,负责大部分的X射线背景。我们将介绍XMM-牛顿巡天的科学亮点,并简要讨论未来观测的前景,以利用当前和即将到来的X射线设施进行XMM深度巡天科学。
We present new joint XMM-Newton and NuSTAR observations of APM 08279+5255, a gravitationally-lensed, broad-absorption line quasar ($z=3.91$). After showing a fairly stable flux ($f_{\rm2-10}\simeq4-5.5\times10^{-13}\rm~erg~s^{-1}$) from 2000 to 2008, APM 08279+5255 was found in a fainter state in the latest X-ray exposures ($f_{\rm2-10}\simeq2.7\times10^{-13}\rm~erg~s^{-1}$), which can likely be ascribed to a lower X-ray activity. Moreover, the 2019 data present a prominent Fe K$α$ emission line and do not show any significant absorption line. This fainter state, coupled to the first hard X-ra…
Isolated neutron star candidates from the fourth generation XMM-Newton catalogues
Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences(中国科学院地球化学研究所月球与行星科学中心);Leibniz-Institut für Astrophysik Potsdam (AIP)(波茨坦阿斯特拉物理学会莱布尼茨研究所);Université de Strasbourg, CNRS, Observatoire Astronomique de Strasbourg(斯特拉斯堡大学法国国家科学研究中心斯特拉斯堡天文台);College of Physics, Guizhou University(贵州大学物理学院);Purple Mountain Observatory, Chinese Academy of Sciences(中国科学院紫金山天文台);Guizhou Radio Astronomical Observatory, Guizhou University(贵州大学贵州射电天文台);National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);College of Astronomy and Space Sciences, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院)
Tracking the Iron K$α$ line and the Ultra Fast Outflow in NGC 2992 at different accretion states
塞弗特2星系NGC 2992在2010年被XMM-牛顿观测了8次,然后在2013年再次被观测,而在2015年,它同时被雨燕和NuSTAR观测到。XMM-牛顿总是捕捉到处于微弱状态的源(2-10 keV通量范围从0.3到1.6 $\times10^{-11}$ erg cm $^{-2}$ s $^{-1}$),但NuSTAR显示2-10 keV通量增加到6 $\times10^{-11}$ erg cm $^{-2}$ s $^{-1}$。我们发现了在这种通量状态下具有速度$v_1=0.21\pm0.01c$(在约99%置信水平下检测到)的超快速流出的可能证据。在NGC 2992中的UFO是一致的,只有在吸积率大于爱丁顿光度的2%时,才能在几十个引力半径处被喷射出来。对低通量2010/2013 XMM数据的分析使我们能够确定该物体中的铁K $α$发射线复合体可能是三个不同成分的总和:一个恒定的,窄的,由于来自冷的,遥远的物质的反射(可能是分子环面);一个窄的,但可变的,在明亮的观测中更强烈,一个宽的相对论性的,在吸积盘的最里面的区域发射,这一现象仅在2003年XMM观测中被发现。
We want to explore the geometrical structure and mutual interactions of the innermost components of the broad line radio galaxy (BLRG) 3C 215, with particular interest in the accretion and ejection mechanisms involving the central supermassive black hole (SMBH). We compare these observational features with the ones of the RQ Seyfert 1 galaxies. Investigating their differences it is possible to understand more about the jet launching mechanisms, and why this phenomenon is efficient only in a small fraction of all the AGNs. Using high quality data from a $\sim60$ ks observation with XMM-Newton, …
Low-redshift absorption in the Seyfert galaxy PG 1211+143 -- a distant inflow maintaining off-plane accretion or the gravitational redshift of matter orbiting the SMBH?
We review the Seyfert 1.5 Galaxy ESO 362-G18 for exploring the origin of the soft X-ray excess. The Warm Corona and Relativistic Reflection models are two main scenarios to interpret the soft X-ray excess in AGNs at present. We use the simultaneous X-ray observation data of XMM-Newton and NuSTAR on Sep. 24th, 2016 to perform spectral analysis in two steps. First, we analyze the time-average spectra by using Warm Corona and Relativistic Reflection models. Moreover, we also explore the Hybrid model, Double Reflection model and Double Warm Corona model. We find that both of Warm Corona and Relati…
The rise and decline of a transient obscuration event in a moderately distant type-I quasar
Institute for Astronomy Astrophysics Space Applications and Remote Sensing (IAASARS), National Observatory of Athens(雅典国家天文台天文学、天体物理学、空间应用与遥感研究所);Department of Astronomy, University of Geneva(日内瓦大学天文学系);Instituto de Estudios Astrofísicos, Facultad de Ingeniería y Ciencias, Universidad Diego Portales(迭戈帕塔莱斯大学工程与科学学院天体物理研究所)