Results 11 to 20 of about 78,490 (277)

On the Unification of Active Galactic Nuclei [PDF]

open access: yesThe Astrophysical Journal, 2012
The inevitable spread in properties of the toroidal obscuration of active galactic nuclei (AGNs) invalidates the widespread notion that type 1 and 2 AGNs are intrinsically the same objects, drawn randomly from the distribution of torus covering factors ...
Alonso-Herrero   +19 more
core   +6 more sources

Flux States of Active Galactic Nuclei [PDF]

open access: yesGalaxies, 2019
Blazars are known to show variability on time scales from minutes to years covering a wide range of flux states. Studying the flux distribution of a source allows for various insights.
Daniela Dorner   +28 more
doaj   +6 more sources

Active Galactic Nuclei

open access: yes, 2010
This work represents the final year project for BSc Physics with Astrophysics degree and it mainly focuses on empirical investigation of the photometry of quasars in the Sloan Digital Sky Survey (SDSS) and the UK Infrared Telescope (UKIRT) Infrared Sky ...
Khassen, Yerbol Farkhatuly
core   +2 more sources

Active galactic nuclei. [PDF]

open access: yesProc Natl Acad Sci U S A, 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 ...
Fabian AC.
europepmc   +8 more sources

Episodic Activity in Active Galactic Nuclei [PDF]

open access: yesProceedings 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

Fuelling active galactic nuclei [PDF]

open access: yesMonthly Notices of the Royal Astronomical Society: Letters, 2007
Abstract 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. We show that the events have a characteristic time-evolution.
J. E. Pringle   +2 more
openaire   +5 more sources

Active Galactic Nuclei

open access: yes, 2022
Introduction into AGN given at SSAASS with focus on radio features of ...
openaire   +4 more sources

Evolution of Active Galactic Nuclei [PDF]

open access: yes, 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 ...
Andrea Merloni, Sebastian Heinz
openaire   +3 more sources

Dust Emission from Active Galactic Nuclei [PDF]

open access: yes, 2002
Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central source, giving rise to Seyfert 1 line spectrum for pole-on viewing and Seyfert 2 characteristics in edge-on sources.
Antonucci R.   +7 more
core   +4 more sources

NuSTAR Observations of a Heavily X-Ray-obscured AGN in the Dwarf Galaxy J144013+024744

open access: yesThe Astrophysical Journal, 2023
We present a multiwavelength analysis of the dwarf Seyfert 2 galaxy J144013+024744, a candidate obscured active galactic nucleus (AGN) thought to be powered by an intermediate-mass black hole (IMBH, M _• ≈ 10 ^4 −10 ^6 M _⊙ ) of mass M _• ∼ 10 ^5.2 M _⊙ .
Shrey Ansh   +12 more
doaj   +1 more source

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