Results 1 to 10 of about 16,702 (151)
Elusive active galactic nuclei [PDF]
Monthly Notices of the Royal Astronomical Society, 2003 A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically 'elusive'. X-ray observations are an optimal tool to identify this class of objects.
BIANCHI, STEFANO +21 more
core +6 more sources
Fuelling active galactic nuclei [PDF]
Monthly Notices of the Royal Astronomical Society: Letters, 2007 We suggest that most nearby active galactic nuclei are fed by a series of small-scale, randomly oriented accretion events. Outside a certain radius these events promote rapid star formation, while within it they fuel the supermassive black hole.
A. R. King (7601711) +1 more
core +4 more sources
, 1990 Starting with this volume, the Lecture Notes of the renowned Advanced Courses of the Swiss Society for Astrophysics and Astronomy will be published annually.
Woltjer, L, Blandford, RD, Netzer, H
core +3 more sources
Proceedings of the National Academy of Sciences, 1999 Active galactic nuclei are the most powerful, long-lived objects in the Universe. Recent data confirm the theoretical idea that the power source is accretion into a massive black hole. The common occurrence of obscuration and outflows probably means that the contribution of active galactic nuclei to the power density of the Universe has been ...
+5 more sources
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
doaj +1 more source
Evolution of Active Galactic Nuclei [PDF]
, 2013 [Abriged] Supermassive black holes (SMBH) lurk in the nuclei of most massive galaxies, perhaps in all of them. The tight observed scaling relations between SMBH masses and structural properties of their host spheroids likely indicate that the processes fostering the growth of both components are physically linked, despite the many orders of magnitude ...
Merloni, A., Heinz, S.
openaire +3 more sources
Episodic Activity in Active Galactic Nuclei [PDF]
Proceedings of 25th Texas Symposium on Relativistic Astrophysics — PoS(Texas 2010), 2011 7 pages, 2 figues, 25th Texas Symposium, Heidelberg, Germany; http://pos.sissa.it/archive/conferences/123/014/Texas%202010_014 ...
Nandi, S. +3 more
openaire +3 more sources
Active galactic nuclei: what’s in a name? [PDF]
The Astronomy and Astrophysics Review, 2017 Accepted for publication in Astronomy & Astrophysics Review, 56 pages, 25 ...
P. Padovani +10 more
openaire +3 more sources
The Astrophysical Journal, 2023 We report on the 2019 XMM-Newton+NuSTAR monitoring campaign of the Seyfert galaxy NGC 2992, observed at one of its highest flux levels in the X-rays.
Alfredo Luminari +10 more
doaj +1 more source
Atoms, 2017 We present the first results of medium-band photometric observations on the 1m Schmidt Telescope of Byurakan Astrophysical Observatory (Armenia). The object sample was created in the SA68 field.
Sergey Kotov, Sergey Dodonov
doaj +1 more source