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

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We present theoretical CIV 1548,1550 absorption line profiles for QSOs calculated assuming the accretion disk wind (ADW) scenario. The results suggest that the multiple absorption troughs seen in many QSOs may be due to the discontinuities…

星系天体物理 · 物理学 2013-11-22 Nicolas A. Pereyra

The broad-line region (BLR) of active galactic nuclei (AGN) is an essential component, yet its small size keeps its origin, structure, and kinematics uncertain. Infrared interferometry with VLTI/GRAVITY is now resolving BLR-scale emission,…

星系天体物理 · 物理学 2026-03-12 Keiichi Wada , Tohru Nagao , Taro Shimizu , Daryl Joe D. Santos , Jinyi Shangguan , Richard Davies

We correlate the ROSAT 1/4 keV all-sky survey with the Leiden/Dwingeloo HI survey, looking for soft X-ray signatures of prominent high-velocity-cloud (HVC) complexes. We study the transfer of 1/4 keV photons through the interstellar medium…

天体物理学 · 物理学 2007-05-23 J. Kerp , W. B. Burton , R. Egger , M. J. Freyberg , Dap Hartmann , P. M. W. Kalberla , U. Mebold , J. Pietz

Quasar broad emission lines are largely powered by photoionization from the accretion continuum. Increased central luminosity will enhance line emissivity in more distant clouds, leading to increased average distance of the…

The tendency of some diffuse interstellar band (DIB) carriers to concentrate in the outer, UV-illuminated layers of molecular clouds (MCs)--the ``skin effect''--makes their spatial distribution a powerful probe of their physical nature. We…

星系天体物理 · 物理学 2026-03-09 He Zhao , Lu Li

Optical emission from actively accreting X-ray binaries is dominated by X-ray reprocessing on the outer disk. In the regime of supercritical accretion, strong radiation will power a massive wind that is optically thick and nearly spherical,…

高能天体物理现象 · 物理学 2019-10-09 Yuhan Yao , Hua Feng

The origin, geometry and kinematics of the broad line region (BLR) gas in quasars and active galactic nuclei (AGN) are uncertain. We demonstrate that clumpy biconical disc winds illuminated by an AGN continuum can produce BLR-like spectra.…

We present far-UV HST/COS spectra of four nearby BL Lac Objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or…

宇宙学与河外天体物理 · 物理学 2015-05-27 John T. Stocke , Charles W. Danforth , Eric S. Perlman

In studying the formation of massive stars, it is essential to consider the strong radiative feedback on the stars' natal environments from their high luminosities ($10^4 \sim 10^6 L_\odot$). Given that massive stars contract to…

太阳与恒星天体物理 · 物理学 2018-07-11 Nathaniel Kee , Stan Owocki , Rolf Kuiper

We present a new model to explain the appearance of red/blue-shifted broad low-ionization emission lines, especially emission lines in optical band, which is commonly considered as an indicator of radial motion of the line emitting gas in…

宇宙学与河外天体物理 · 物理学 2015-05-13 Xue-GUang Zhang , Deborah Dultzin , Ting-Gui Wang , Guinevere Kaufmann

Observations have shown that the optical colors of Galactic cirrus clouds differ significantly from those of extragalactic sources; thus, they can be used to distinguish Galactic cirrus from extragalactic low surface brightness (LSB)…

星系天体物理 · 物理学 2025-10-23 Kwang-Il Seon , Jongwan Ko , Woowon Byun , Jaehyun Lee , Young-Soo Jo

Supercritical accretion onto compact objects is expected to drive optically thick winds, resulting in observed X-ray emission as a function of viewing angle. However, their optical emission, either from the outer accretion disk or companion…

高能天体物理现象 · 物理学 2025-08-13 Xiaohong Tang , Hua Feng

Recent observations of Broad Absorption Line (BAL) quasars demonstrated that the soft X-ray emission of these objects is extremely weak and convincing evidence for very strong absorption by a high column density (~ 10^23.5 cm^-2) was…

天体物理学 · 物理学 2009-10-31 T. G. Wang , W. Brinkmann , W. Yuan , J. X. Wang , Y. Y. Zhou

We present integral field spectroscopy of the nebular line emission in a sample of 9 brightest cluster galaxies (BCGs). The sample was chosen to probe both cooling flow and non-cooling flow clusters, as well as a range of cluster X-ray…

宇宙学与河外天体物理 · 物理学 2015-05-13 L. O. V. Edwards , C. Robert , M. Mollá , S. L. McGee

Cumulative optical and infrared emission from galaxies accumulated over cosmological time scales, the extragalactic background light (EBL), could be probed by complementary techniques of direct observations and source counting in the…

高能天体物理现象 · 物理学 2020-01-15 A. Korochkin , A. Neronov , D. Semikoz

We discuss the effects of microlensing on the broad emission lines (BELs) of QSOs in the light of recent determinations of the size of the broad line region (BLR) and its scaling with QSO luminosity. Microlensing by star-sized objects can…

天体物理学 · 物理学 2009-11-07 C. Abajas , E. Mediavilla , J. A. Munoz , L. C. Popovic , A. Oscoz

We present a physical model for origin of the cosmic diffuse infrared background (CDIRB). By utilizing the observed stellar mass function and its evolution as input to a semi-empirical model of galaxy formation, we isolate the physics…

宇宙学与河外天体物理 · 物理学 2015-05-18 Joshua D. Younger , Philip F. Hopkins

We investigated the properties of cholesteric liquid crystals (CLCs) being in external static magnetic field directed along the helix axis. We have shown that in the case of the wavelength dependence of magneto-optic activity parameter, and…

光学 · 物理学 2023-08-17 A. H. Gevorgyan

X-rays illuminating the accretion disc in active galactic nuclei give rise to an iron K line and its associated reflection spectrum which are lagged behind the continuum variability by the light-travel time from the source to the disc. The…

高能天体物理现象 · 物理学 2018-05-16 Misaki Mizumoto , Chris Done , Kouichi Hagino , Ken Ebisawa , Masahiro Tsujimoto , Hirokazu Odaka

We consider the fuelling of the central massive black hole in Active Galactic Nuclei, through an inhomogeneous accretion flow. Performing simple analytical treatments, we show that shocks between elements (clumps) forming the accretion flow…

天体物理学 · 物理学 2009-11-13 W. Ishibashi , T. J. -L. Courvoisier