Results 121 to 130 of about 9,238,867 (222)
Discovery of Changing-look Behavior in AGN NGC 3822: A Long-term Multiwavelength Study
The Astrophysical JournalWe present a comprehensive long-term multiwavelength study of the active galactic nucleus NGC 3822, based on 17 yr (2008–2025) of X-ray, ultraviolet (UV), and optical observations. The data set includes observations from Swift , XMM - Newton, and NuSTAR,
Narendranath Layek +9 more
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Cosmic X-ray surveys of active galactic nuclei: The synergy between X-ray and infrared observations
, 2017 We briefly review the synergy between X-ray and infrared observations for active galactic nuclei (AGNs) detected in cosmic X-ray surveys, primarily with XMM-Newton, Chandra, and NuSTAR. We focus on two complementary aspects of this X-ray–infrared synergy:
D. M. Alexander, Alexander, D.M.
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X-ray and optical studies of active galactic nuclei [PDF]
, 1991 Active Galactic Nuclei are among the most highly energetic objects in the universe, but they are still poorly understood. Of particular interest at the moment is the existence and effects of massive accretion disks near the centre of AGN. Accretion disks
Mittaz, Jonathan Patrick Duncan
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A Systematic Search for Active Galactic Nuclei Obscuration Variability in the Chandra Archive
The Astrophysical JournalThe nature of the obscuring material in active galactic nuclei (AGN) can be studied by measuring changes in the line-of-sight column density, N _H,LOS , over time. This can be accomplished by monitoring AGN over long periods of time and at all timescales.
Isaiah S. Cox +7 more
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On the Extended Soft X-Ray and Fe Kα Emission in NGC 1068
The Astrophysical JournalThe soft X-ray excess and Fe K α emission lines are widely observed in Seyfert galaxies, with their origin still in debate. We present a detailed spatially resolved image and spectral analysis of the Seyfert 2 galaxy NGC 1068 using high-resolution ...
Songbo Gao, Hongxing Yin, Shaoming Hu
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Active X-ray optics for the next generation of X-ray space telescopes [PDF]
, 2010 Described within is the design, manufacture, metrology and X-ray testing of an active X-ray prototype intended for the next generation of X-ray telescopes.
Atkins, C.
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First X-Ray Polarimetric View of a Low-luminosity Active Galactic Nucleus: The Case of NGC 2110
The Astrophysical JournalLow-luminosity active galactic nuclei (LLAGN) provide a unique view of Comptonization and nonthermal emission from accreting black holes in the low accretion rate regime.
Sudip Chakraborty +23 more
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Systematic Monitoring of Extreme X-Ray Variability from Weak-line Quasars
The Astrophysical JournalWe present the results of a multicycle Chandra program to systematically monitor the X-ray variability of 10 weak-line quasars (WLQs) that previously had limited multiepoch X-ray observations.
Madison Reich +7 more
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, 2002 The following topics were dealt with: Soft X-ray spectral complexity, Fe K line profiles, warm absorbing and broad absorption line gas, Seyfert 2s and AGN unification, AGN as cosmological probes, narrow- line Seyfert 1s. (HSI)Available from TIB Hannover:
Kahn, S. +5 more
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X-ray and UV emission from active galactic nuclei Abstracts of contributed papers
, 1984 SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische ...
Max-Planck-Institut fuer Physik und Astrophysik, Garching (Germany, F.R.). Inst. fuer Extraterrestrische Physik
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