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相关论文: Intervening BLR Clouds' Effects on Optical/UV Spec…

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In order to contribute to the general effort aiming at the improvement of our knowledge about the physical conditions within the Broad Line Region (BLR) of Active Galactic Nuclei (AGN), here we present the results achieved by our analysis…

天体物理学 · 物理学 2009-03-12 G. La Mura , L. Č. Popović , S. Ciroi , P. Rafanelli , D. Ilić

The strong broad emission lines in the optical and UV spectra of Active Galactic Nuclei (AGN) are important for several reasons. Not only do they give us information about the structure of the AGN, their properties are now used to estimate…

天体物理学 · 物理学 2007-05-23 Karen M. Leighly , Darrin Casebeer

Velocity-resolved reverberation mapping suggests that the broad-line regions (BLRs) of AGNs can have significant net inflow. We use the STOKES radiative transfer code to show that electron and Rayleigh scattering off the BLR and torus…

天体物理学 · 物理学 2015-03-13 C. Martin Gaskell , Rene W. Goosmann

The high-ionization lines of the broad-line region (BLR) of thermal active galactic nuclei (AGNs) show blueshifts of a few hundred km/s to several thousand km/sec with respect to the low-ionization lines. This has long been thought to be…

星系天体物理 · 物理学 2016-02-03 C. Martin Gaskell , Rene W. Goosmann

We analyze the broad H$\beta$ line profile variability of the "changing look" active galactic nucleus (CL-AGN) NGC 3516 over a long period of 25 years. The observed change in the broad line profile may indicate a change in the geometry of…

In cold molecular clouds submillimetre emission lines are excited by the ambient radiation field. The pumping is dominated by the cosmic microwave background (CMB). It is usual in molecular line radiative transfer modelling to simply assume…

天体物理学 · 物理学 2009-11-10 M. P. Redman , J. M. C. Rawlings , J. A. Yates , D. A. Williams

The masses of central massive black holes in BL Lac objects are estimated from their host galaxy absolute magnitude at R-band by using the empirical relation between absolute magnitude of host galaxy and black hole mass. Only a small…

天体物理学 · 物理学 2009-11-10 Xinwu Cao

There is increasing evidence that the highly ionized multiphase components of AGN disk winds may be due to thermal instability. The ions responsible for forming the observed X-ray absorption lines may only exist in relatively cold clumps…

星系天体物理 · 物理学 2017-02-08 Tim Waters , Daniel Proga , Randall Dannen , Tim Kallman

Star formation is regulated through a variety of feedback processes. In this study, we treat feedback by X-rays and discuss its implications. Our aim is to investigate whether star formation is significantly affected when a star forming…

星系天体物理 · 物理学 2010-09-03 S. Hocuk , M. Spaans

I summarise and analyse key problems with observations of the UV bump in Active Galactic Nuclei (AGN), and especially the accretion disc interpretation - the temperature problem, the ionisation problem, the timescale problem, and the…

宇宙学与河外天体物理 · 物理学 2015-05-30 Andy Lawrence

Weak spectral features in BL Lacertae objects (BL Lac) often provide a unique opportunity to probe the inner region of this rare type of active galactic nucleus. We present a Hubble Space Telescope/Cosmic Origins Spectrograph observation of…

We study the influence of gravitational microlensing on the AGN Fe K-alpha line confirming that unexpected enhancements recently detected in the iron line of some AGNs can be produced by this effect. We use a ray tracing method to study the…

天体物理学 · 物理学 2009-11-07 L. C. Popovic , E. G. Mediavilla , P. Jovanovic , J. A. Munoz

Mrk 590 is a Changing Look AGN currently in an unusual repeat X-ray and UV flaring state. Here, we report on deep X-ray observations with XMM-Newton, NuSTAR, and NICER, obtained at a range of X-ray flux levels. We detect a prominent soft…

星系天体物理 · 物理学 2025-03-18 Daniel Lawther , Marianne Vestergaard , Sandra Raimundo , Xiaohui Fan , Jun Yi Koay

The optical-ultraviolet continuum from active galactic nuclei (AGN) seem to originate from optically thick and/or thin disks, and occasionally from associated circumnuclear starburst regions. These different possible origins can, in…

天体物理学 · 物理学 2007-05-23 A. Yonehara , S. Mineshige , J. Fukue , M. Umemura , E. L. Turner

Since the launch of the Einstein X-ray Observatory in the 1970s, a number of broad absorption features have been reported in the X-ray spectra of BL Lac objects. These features are often interpreted as arising from high velocity outflows…

高能天体物理现象 · 物理学 2015-05-27 Taotao Fang , David A. Buote , Philip J. Humphrey , Claude R. Canizares

Periodic quasars have been suggested to host supermassive binary black holes (BBHs) in their centers, and their optical/UV periodicities are interpreted as caused by either the Doppler-boosting (DB) effect of continuum emission from the…

星系天体物理 · 物理学 2021-04-07 Xiang Ji , Youjun Lu , Junqiang Ge , Changshuo Yan , Zihao Song

Line profile distortions are commonly observed in gravitationally lensed quasar spectra. These distortions are caused by microlensing from the stars in the lensing galaxy, which produce differential magnification of spatially and…

星系天体物理 · 物理学 2021-10-27 Damien Hutsemékers , Dominique Sluse

We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This observation was carried out simultaneously with HST-STIS and FUSE, in the context of a multiwavelength study of this source. The Chandra pointings were spread over…

The broad-line region (BLR) disappears in many low-luminosity AGNs, the reason of which is still controversial. The BLRs in AGNs are believed to be associated with the outflows from the accretion disks. Most of the low-luminosity AGNs…

高能天体物理现象 · 物理学 2015-05-20 Xinwu Cao

We consider an accretion-disc origin for the broad and luminous forbidden-line emission observed in ultraluminous X-ray (ULX) sources CXOJ033831.8-352604 and XMMU 122939.7+075333 in globular clusters hosted by elliptical galaxies NGC 1399…

宇宙学与河外天体物理 · 物理学 2015-05-19 Ryan L. Porter