Results 1 to 10 of about 71,684 (84)

Obscured Active Galactic Nuclei [PDF]

open access: yesAIP Conference Proceedings, 2000
The properties of the absorption in type 2, narrow line AGNs are reviewed by focusing on the X-ray indicators. I discuss the properties of the cold absorbing medium (the putative torus) and of the reprocessed components, as well as their implications for
Maiolino, R.
core   +5 more sources

Fuelling Active Galactic Nuclei [PDF]

open access: yesMonthly 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.
King, A. R., Pringle, J. E.
core   +4 more sources

Elusive Active Galactic Nuclei [PDF]

open access: yesMonthly 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.
A. Comastri   +24 more
core   +9 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   +3 more sources

Heating Hot Atmospheres with Active Galactic Nuclei

open access: yesAnnual Review of Astronomy and Astrophysics, 2007
High resolution X-ray spectroscopy of the hot gas in galaxy clusters has shown that the gas is not cooling to low temperatures at the predicted rates of hundreds to thousands of solar masses per year.
Arnaud M   +12 more
exaly   +3 more sources

Active galactic nuclei [PDF]

open access: yesProceedings 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

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

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 ...
Merloni, A., Heinz, S.
openaire   +3 more sources

Active galactic nuclei: what’s in a name? [PDF]

open access: yesThe Astronomy and Astrophysics Review, 2017
Accepted for publication in Astronomy & Astrophysics Review, 56 pages, 25 ...
P. Padovani   +10 more
openaire   +3 more sources

Active galactic nuclei at z ~ 1.5: III. Accretion discs and black hole spin [PDF]

open access: yes, 2016
This is the third paper in a series describing the spectroscopic properties of a sample of 39 AGN at $z \sim 1.5$, selected to cover a large range in black hole mass ($M_{BH}$) and Eddington ratio ($L/L_{Edd}$). In this paper, we continue the analysis of
Capellupo, Daniel M.   +4 more
core   +2 more sources

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