Results 11 to 20 of about 1,130 (187)
X-Ray Eclipses of Active Galactic Nuclei [PDF]
The Astrophysical Journal, 2017 Abstract X-ray variation is a ubiquitous feature of active galactic nuclei (AGNs); however, its origin is not well understood. In this paper, we show that the X-ray flux variations in some AGNs, and correspondingly, the power spectral densities (PSDs) of the variations, may be interpreted as being caused by absorptions of eclipsing ...
Fupeng Zhang, Qingjuan Yu, Youjun Lu
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Search for X-ray occultations in active galactic nuclei [PDF]
Monthly Notices of the Royal Astronomical Society, 2014 Accepted for publication in MNRAS. 15 pages, 7 figures. Table 2 not included, will be available in the published version.
G. Torricelli Ciamponi +3 more
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X-ray absorption and reflection in active galactic nuclei [PDF]
The Astronomy and Astrophysics Review, 2009 Accepted for publication in the Astronomy and Astrophysics Review. 58 pages, 9 figures.
Turner, T, Miller, L
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Clustering of X-ray selected active galactic nuclei [PDF]
Monthly Notices of the Royal Astronomical Society, 1998 A total of 235 Active Galactic Nuclei (AGN) from two different soft X-ray surveys (the ROSAT Deep Survey -DRS- and the ROSAT International X-ray Optical Survey -RIXOS-) with redshifts between 0 and 3.5 are used to study the clustering of X-ray selected AGN and its evolution.
Carrera, Francisco J. +7 more
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Rapid X-Ray Variability in Active Galactic Nuclei [PDF]
Symposium - International Astronomical Union, 1986 SummaryRecent EXOSAT observations of active galactic nuclei are presented. Unlike earlier X-ray satellites (all of which flew in low earth orbit), the deep orbit of EXOSAT allows long continuous observations of celestial X-ray sources, uninterrupted by earth occultation etc.
P. Barr +4 more
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Variability and the X-ray/UV ratio of active galactic nuclei [PDF]
Astronomy and Astrophysics, 2010 16 pages, 10 figures, 1 table.
VAGNETTI, FAUSTO +3 more
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X-Ray Observations of Active Galactic Nuclei [PDF]
Symposium - International Astronomical Union, 1983 HEAO 1 A2 and Einstein SSS spectral observations of Seyfert galaxies and BL Lac objects suggest that in both cases, the X-ray emission is due to relativistic particles. The five BL Lac objects have very soft spectra and at higher energies (above 10 keV) may have hard tails.
C. Megan Urry +4 more
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X-Ray Variability of Active Galactic Nuclei [PDF]
Highlights of Astronomy, 1983 X-ray variability of active galactic nuclei is commonplace on scales from days to years. It also occurs, although rarely, on time scales as short as 200 seconds. Both these statements must be strongly qualified by the irregularity and insensitivity of the available observations. In the X-rays we expect that we are seeing deep within the active nucleus,
Daniel A. Schwartz +2 more
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Unwrapping the X‐ray spectra of active galactic nuclei [PDF]
Astronomische Nachrichten, 2016 AbstractActive galactic nuclei (AGN) are complex phenomena. At the heart of an AGN is a relativistic accretion disk around a spinning supermassive black hole (SMBH) with an X‐ray emitting corona and, sometimes, a relativistic jet. On larger scales, the outer accretion disk and molecular torus act as the reservoirs of gas for the continuing AGN activity.
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X-RAY LUMINOSITY FUNCTIONS OF ACTIVE GALACTIC NUCLEI [PDF]
Multiwavelength AGN Surveys, 2004 To appear in the proceedings of the conference "Multiwavelenth AGN Surveys", held in Cozumel, Mexico, December 2003 (invited talk).
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