Results 11 to 20 of about 37,389 (216)
A direct image of the obscuring disk surrounding an active galactic nucleus [PDF]
Nature, 1997 Active galactic nuclei (AGN) are generally accepted to be powered by the release of gravitational energy in a compact accretion disk surrounding a massive black hole. Such disks are also necessary to collimate powerful radio jets seen in some AGN.
A Capetti +30 more
core +4 more sources
X-ray Insight into High-Energy Processes in Extreme Galactic Nuclear Environment
Universe, 2022 Nuclear regions of galaxies apparently play a disproportionately large role in regulating their formation and evolution. How this regulation works, however, remains very uncertain.
Q. Daniel Wang
doaj +1 more source
X-Ray Emission of Ultraviolet Variable Active Galactic Nucleus Candidates
The Astronomical Journal, 2023 We analyze the X-ray properties of a sample of 23 high-probability active galactic nucleus (AGN) candidates with ultraviolet variability identified in Wasleske et al.
Erik J. Wasleske, Vivienne F. Baldassare
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Magnetohydrodynamics Simulations of Active Galactic Nucleus Disks and Jets [PDF]
Annual Review of Astronomy and Astrophysics, 2020 There is a broad consensus that accretion onto supermassive black holes and consequent jet formation power the observed emission from active galactic nuclei (AGNs). However, there has been less agreement about how jets form in accretion flows, their possible relationship to black hole spin, and how they interact with the surrounding medium.
Davis, Shane W., Tchekhovskoy, Alexander
openaire +2 more sources
ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK [PDF]
The Astrophysical Journal, 2013 We show, using global 3D grid-based hydrodynamical simulations, that Ultra Fast Outflows (UFOs) from Active Galactic Nuclei (AGN) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy. The AGN wind interacts strongly with the inhomogeneous, two-phase ISM consisting of dense clouds embedded in a ...
Wagner, A. Y. +2 more
openaire +3 more sources
Active galactic nucleus feedback in NGC 3982
Astronomy & Astrophysics, 2022 The energetic feedback from supermassive black holes can influence star formation at the centres of galaxies. Observational evidence for active galactic nucleus (AGN) impact on star formation can be searched for in galaxies by combining ultraviolet imaging and optical integral field unit data. The ultraviolet flux directly traces recent star formation,
P. Joseph, K. George, K. T. Paul
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A possible active galactic nucleus in M82? [PDF]
New Astronomy Reviews, 1999 MERLIN and VLA observations of the galaxy M82 have detected a jet-like elongated radio continuum feature emanating from one of the compact sources, 44.01+59.6, embedded in the starburst. The proximity of this source to the dynamical centre of M82 led us to suspect that it could be a weak active nucleus rather than a supernova remnant.
K. A. Wills +3 more
openaire +1 more source
NGC 1808: active galactic nucleus or starburst? [PDF]
Monthly Notices of the Royal Astronomical Society, 1992 We present optical and near-infrared images, together with long-slit spectra at red wavelengths, of NGC 1808. The complex morphology of hotspots seen at short wavelengths may be the result of dust obscuration. Our data (namely the equivalent width of the Ca II triplet and broad-band colours) suggest the presence of red supergiants, associated with a ...
D. A. Forbes, C. Boisson, M. J. Ward
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Black hole variability and the star formation-active galactic nucleus connection : do all star-forming galaxies host an active galactic nucleus? [PDF]
, 2014 We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys.
Alexander, D.M. +6 more
core +2 more sources
ACTIVE GALACTIC NUCLEUS FEEDBACK WORKS BOTH WAYS [PDF]
The Astrophysical Journal, 2013 Simulations of galaxy growth need to invoke strong negative feedback from active galactic nuclei (AGNs) to suppress the formation of stars and thus prevent the over-production of very massive systems. While some observations provide evidence for such negative feedback, other studies find either no feedback or even positive feedback, with increased star
Zinn, Peter C. +3 more
openaire +2 more sources