We present XMM and Suzaku observations of the Broad-Line Radio Galaxy (BLRG) 3C390.3. The Fe Ka line has a width FWHM ~ 8,800 km/s, consistent within a factor two with the width of the double-peaked H_alpha line, suggesting an origin from the Broad Line Region. The data show for the first time a weak, broad bump extending from 5 to 7 keV. When fitted with a Gaussian, its centroid energy is 6.6 keV in the source's rest-frame with FWHM of 43,000 km/s and EW of 50 eV; its most likely interpretation is emission from He-like Fe (Fe XXV), suggesting the presence of an ionized medium in the inner regions of 3C390.3. The broad-band 0.5-100 keV continuum is well described by a single power law with photon index Gamma=1.6 and cutoff energy 157 keV, plus cold reflection with strength R=0.5. In addition, ionized reflection is required to account for the 6.6 keV bump in the broad-band continuum, yielding an ionization parameter xi ~ 2700 ergs cm s^-1; the inner radius of the ionized reflector is constrained to be larger than 20 r_G, although this result depends on the assumed emissivity profile of the disk. If true, we argue that the lack of broad Fe K emission from within 20 r_G indicates that the innermost regions of the disk in 3C390.3 are obscured and/or poorly illuminated. While the SED of 3C390.3 is generally dominated by accretion-related continuum, during accretion low states the jet can significantly contribute in the optical to X-ray bands via synchrotron self-Compton emission. (Abridged)
Linking {\it Fermi} blazars and radio galaxies through accretion and jet radiation mechanisms
Università di Padova（帕多瓦大学）；Istituto Nazionale di Fisica Nucleare, Sezione di Padova（意大利国家核物理研究所帕多瓦分部）；Guangzhou University（广州大学）；INAF - Istituto di Radioastronomia（意大利国家天体物理研究所射电天文台）；Astronomy Science and Technology Research Laboratory of Department of Education of Guangdong Province（广东省教育厅天文学科学与技术研究实验室）；Wuhu Vocational Technical University（芜湖职业技术学院）；Institute of Astronomy and National Astronomical Observatory（天文学研究所与国家天文观测站）
Radio-X-ray Time Lags in GX 339-4: Probing Magnetic Field Transport in Black Hole Accretion
Institute for Astronomy, School of Physics, Zhejiang University（浙江大学物理学院天体物理研究所）；Department of Astronomy, School of Physics and Technology, Wuhan University（武汉大学物理科学与技术学院天文学系）；Shanghai Astronomical Observatory, Chinese Academy of Sciences (CAS)（中国科学院上海天文台）
The stellar binary system LS I +61303, composed of a compact object in an eccentric orbit around a B0 Ve star, emits from radio up to gamma-ray energies. The orbital modulation of radio spectral index, X-ray, and GeV gamma-ray data suggests the presence of two peaks. This two-peaked profile is in line with the accretion theory predicting two accretion-ejection events for LS I +61303 along the 26.5 d orbit. However, the existing multiwavelength data are not simultaneous. In this paper, we report the results of a campaign covering radio, X-ray, and gamma-ray observations of the system along one …
The Multi-Wavelength Context of Delayed Radio Emission in TDEs: Evidence for Accretion-Driven Outflows
University of Arizona（亚利桑那大学）；University of California, Berkeley（加州大学伯克利分校）；Center for Astrophysics | Harvard & Smithsonian（哈佛与史密森尼天体物理中心）；Northwestern University（西北大学）；University of Utah（犹他大学）；Radboud University（拉德堡德大学）；University of Oregon（俄勒冈大学）
We study the relativistic, inviscid, advective accretion flow around the black holes and investigate a key feature of the accretion flow, namely the shock waves. We observe that the shock-induced accretion solutions are prevalent and such solutions are commonly obtained for a wide range of the flow parameters, such as energy (${\cal E}$) and angular momentum ($λ$), around the black holes of spin value $0\le a_{\rm k} < 1$. When the shock is dissipative in nature, a part of the accretion energy is released through the upper and lower surfaces of the disc at the location of the shock transition.…
3FGL J1544.6-1125 is a candidate transitional millisecond pulsar (tMSP). Similar to the well-established tMSPs - PSR J1023+0038, IGR J18245-2452, and XSS J12270-4859 -- 3FGL J1544.6-1125 shows $γ$-ray emission and discrete X-ray "low" and "high" modes during its low-luminosity accretion-disk state. Coordinated radio/X-ray observations of PSR J1023+0038 in its current low-luminosity accretion-disk state showed rapidly variable radio continuum emission-possibly originating from a compact, self-absorbed jet, the "propellering" of accretion material, and/or pulsar moding. 3FGL J1544.6-1125 is curr…
A New Accretion Disk Around the Missing Link Binary System PSR J1023+0038
PSR J1023+0038是一个特殊的系统，用于了解缓慢旋转的中子星如何通过伴星的吸积旋转到毫秒旋转周期。从2007年到2013年作为射电脉冲星观测，光学数据显示该系统在2000/2001年有一个吸积盘。从2013年6月底开始，射电脉冲星已经无法被探测到，这表明它回到了以前的吸积盘状态，在那里系统更像是一个X射线双星。在这封信中，我们报告了有史以来第一次对活跃阶段进行的有针对性的X射线观测，并补充了2013年10月收集的紫外/光学和射电观测。我们找到了强有力的证据，确实是一个吸积盘最近形成的系统中，我们报告的快速X射线变化的检测跨越约两个数量级的光度。在X射线光变曲线的低通量状态或任何其他时间，都没有看到射电脉动。
An Accretion Disc-Irradiation Hybrid Model for The Optical/UV Variability in Radio-Quiet Quasars
类星体的光/紫外光变与类星体的其它性质，如光度、黑洞质量和静止坐标系波长等都有密切的关系。然而，变异性的起源至今仍是一个谜。在这项工作中，我们升级的吸积盘模型（Li & Cao 2008），其中假设的变化是由全球质量吸积率的变化，通过限制盘的大小，以匹配的粘性时间尺度的吸积盘观测到的变化时间尺度，并通过包括照射/X射线后处理，使发射光谱变得陡峭。我们发现这个混合模型可以很好地再现观测到的蓝时亮的趋势，这是用来验证理论模型的一些工作最近。传统的变异幅度与静止帧波长的相关关系也可以用我们的模型很好地拟合。此外，一个弱的正相关性之间的变化幅度和黑洞质量的存在，定性与最近的观测。
It is generally thought that FRII Radio Galaxies host thin optically thick disks, while FRIs are powered by Advected Dominated Accretion Flows. The sources with an efficient engine are optically classified as High Excitation Radio Galaxies (HERGs) and those with an inefficient motor as Low Excitation Radio Galaxies (LERGs). Recently, the study of Radio Galaxies down to mJy fluxes has cast serious doubts on the LERG-FRI and HERG-FRII correspondence, revealing that many LERGs show FRII radio morphologies. The FR catalogs recently compiled by Capetti et al. (2017a,b) and Baldi et al. (2018) have …
Centaurus X-4 (Cen X-4) is a relatively nearby neutron star low-mass X-ray binary that showed outbursts in 1969 and 1979, but has not shown a full outburst since. Due to its proximity and sustained period of quiescence, it is a prime target to study the coupling between accretion and jet ejection in quiescent neutron star low-mass X-ray binaries. Here, we present four MeerKAT radio observations at 1.3 GHz of Cen X-4, combined with NICER and Swift X-ray monitoring. During the first and most sensitive observation, Cen X-4 was in a fully quiescent X-ray state. The three later and shorter observat…
When a black hole accretes close to the Eddington limit, the astrophysical jet is often accompanied by radiatively driven, wide-aperture and mildly relativistic winds. Powerful winds can produce significant non-thermal radio emission via shocks. Among the nearby critical accretion quasars, PDS 456 has a very massive black hole (about one billion solar masses), shows a significant star-forming activity (about seventy solar masses per year) and hosts exceptionally energetic X-ray winds (power up to twenty per cent of the Eddington luminosity). To probe the radio activity in this extreme accretio…
We report here radio follow-up observations of the optical Tidal Disruption Event (TDE) AT 2019azh. Previously reported X-ray observations of this TDE showed variability at early times and a dramatic increase in luminosity, by a factor of $\sim 10$, about 8 months after optical discovery. The X-ray emission is mainly dominated by intermediate hard--soft X-rays and is exceptionally soft around the X-ray peak, which is $L_X \sim 10^{43} \rm \, erg \, s^{-1}$. The high cadence $15.5$ GHz observations reported here show an early rise in radio emission followed by an approximately constant light cu…
A Shock-based Interpretation of Radio and X-ray Emission in Active Galactic Nuclei
School of Physics and Astronomy, Yunnan University（云南大学物理与天文学院）；Key Laboratory of Astroparticle Physics of Yunnan Province, Yunnan University（云南省天体粒子物理重点实验室）
Accreting neutron stars in low-mass X-ray binaries show outflows -- and sometimes jets -- in the general manner of accreting black holes. However, the quantitative link between the accretion flow (traced by X-rays) and outflows and/or jets (traced by radio emission) is much less well-understood for neutron stars than for black holes, other than the general observation that neutron stars are fainter in the radio at a given X-ray luminosity. We use data from the deep MAVERIC radio continuum survey of Galactic globular clusters for a systematic radio and X-ray study of six luminous (L_X > 10^34 e…
We studied the relation of accretion-jet power and disk luminosity, especially the jet efficiencies and disk radiative efficiencies for different accretion disks as well as black hole (BH) spin, in order to explore the origin of radio emission in black hole X-ray binaries (BHXBs). We found that jet efficiency increases more rapidly (efficient) than the nearly constant disk radiative efficiency for thin disk component in high accretion regime, which could account for the steep track ($μ>1$) in the observed radio and X-ray luminosity relations ($L_{\rm R}\propto L_{\rm X}^μ$), but the thin disk …
The spectral evolution of transient X-ray binaries can be reproduced by an interplay between two flows separated at a radius $R_J$: a standard accretion disk (SAD) in the outer parts and a jet-emitting disk (JED) in the inner parts. In the previous papers of this series, we recover the spectral evolution in both X-rays and radio for four outbursts of GX339-4 by playing independently with the two parameters: $R_J$ and the accretion rate $\dot{M}_{in}$. In this paper, we compare the time evolution of $R_J$ and $\dot{M}_{in}$ for the four outbursts. We show that despite the undeniable differences…
