Results 11 to 20 of about 50,208 (269)
The Astrophysical Journal, 2023 “Changing-look active galactic nuclei” (CLAGNs) are known to change their apparent types between types 1 and 2, usually accompanied by a drastic change in their luminosity on timescales of years.
Hirofumi Noda +13 more
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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 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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The Astrophysical Journal, 2023 Above ∼3 keV, the X-ray spectrum of active galactic nuclei (AGNs) is characterized by the intrinsic continuum and Compton reflection features. For type-1 AGNs, several regions may contribute to the reflection.
César Ivan Victoria-Ceballos +5 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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The Astrophysical Journal, 2023 To understand the formation and growth of supermassive black holes (SMBHs) and their coevolution with host galaxies, it is essential to know the impact of environment on the activity of active galactic nuclei (AGNs).
Zhensong Hu +16 more
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Sources of X-rays from galaxies [PDF]
, 2011 Galactic X-ray emission is a manifestation of various high-energy phenomena and processes. The brightest X-ray sources are typically accretion-powered objects: active galactic nuclei and low- or high-mass X-ray binaries.
Liu +10 more
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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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The Astrophysical Journal, 2023 1ES1927+654 is a nearby active galactic nucleus (AGN) that has shown an enigmatic outburst in optical/UV followed by X-rays, exhibiting strange variability patterns at timescales of months to years.
Ritesh Ghosh +26 more
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The X-Ray Coronae in NuSTAR Bright Active Galactic Nuclei
The Astrophysical Journal, 2022 Abstract We present a systematic and uniform analysis of NuSTAR data of a sample of 60 SWIFT BAT-selected AGNs with 10–78 keV signal-to-noise ratio (S/N) > 50, 10 of which are radio loud. We measure their high-energy cutoff E cut or coronal temperature T e using three different spectral models to ...
Jia-Lai Kang, Jun-Xian Wang
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