Results 11 to 20 of about 352 (180)

The Reliability of Accretion Disk Inclination Derived from X-Ray Spectroscopy of Active Galaxies

The Astrophysical Journal
The inclination angle of substructures in active galaxies gives insights into physical components from scales of the vicinity of the central black hole to the entire host galaxy. We use the self-consistent reflection spectral model RELXILL to measure the
Rong Du, Yuanze Ding, Luis C. Ho, Ruancun Li   +3 more
doaj   +4 more sources

Star formation and accretion in the circumnuclear disks of active galaxies [PDF]

Astronomy & Astrophysics, 2013
13 pages, 15 figures, 6 tables, accepted at A& ...
Wutschik, S., Schleicher, Dominik Reinhold Georg, Palmer, T. ~S.   +2 more
openaire   +3 more sources

CONNECTION BETWEEN THE ACCRETION DISK AND JET IN THE RADIO GALAXY 3C 111 [PDF]

The Astrophysical Journal, 2011
We present the results of extensive multi-frequency monitoring of the radio galaxy 3C 111 between 2004 and 2010 at X-ray (2.4--10 keV), optical (R band), and radio (14.5, 37, and 230 GHz) wave bands, as well as multi-epoch imaging with the Very Long Baseline Array (VLBA) at 43 GHz.
Chatterjee, Ritaban, Marscher, Alan P., Jorstad, Svetlana G., Markowitz, Alex, Rivers, Elizabeth, Rothschild, Richard E., McHardy, Ian M., Aller, Margo F., Aller, Hugh D., Lahteenmaki, Anne, Tornikoski, Merja, Harrison, Brandon, Agudo, Iv'an, Gomez, Jos'e L., Taylor, Brian W., Gurwell, Mark   +15 more
openaire   +5 more sources

An Accretion Disk Model for the Innermost 200PC of the Galaxy [PDF]

International Astronomical Union Colloquium, 1994
AbstractWe demonstrate that it is possible to understand observed radial velocities of molecular clouds close to the Galactic Center as being due to motion of this material in an accretion disk. Our models indicate a stationary disk with a radial mass flow rate of 10-1.8 Mʘ/yr with a viscosity of 1.9 · 103 pc km/s at 100 pc from the Galactic Center and
W.J. Duschl, S.v. Linden, P.L. Biermann
openaire   +1 more source

SHRINKING GALAXY DISKS WITH FOUNTAIN-DRIVEN ACCRETION FROM THE HALO [PDF]

The Astrophysical Journal, 2014
Star formation in most galaxies requires cosmic gas accretion because the gas consumption time is short compared to the Hubble time. This accretion presumably comes from a combination of infalling satellite debris, cold flows, and condensation of hot halo gas at the cool disk interface, perhaps aided by a galactic fountain.
Elmegreen, Bruce G., Struck, Curtis, Hunter, Deidre A.   +2 more
openaire   +2 more sources

What Kinds of Accretion Disks Are There in the Nuclei of Radio Galaxies? [PDF]

Publications of the Astronomical Society of Japan, 2010
It seems to be a widely accepted opinion that the types of accretion disks (or flows) generally realized in the nuclei of radio galaxies and in further lower mass-accretion rate nuclei are inner, hot, optically thin, radiatively inefficient accretion flows (RIAFs) surrounded by outer, cool, optically thick, standard-type accretion disks.
Kaburaki, Osamu, Nankou, Takanobu, Tamura, Naoya, Wajima, Kiyoaki   +3 more
openaire   +2 more sources

On the Accretion Origin of a Vast Extended Stellar Disk around the Andromeda Galaxy [PDF]

The Astrophysical Journal, 2005
We present the discovery of an inhomogenous, low-surface brightness, extended disk-like structure around the Andromeda galaxy (M31) based on a large kinematic survey of more than 2800 stars with the Keck/DEIMOS spectrograph. The stellar structure spans radii from 15 kpc out to ~40 kpc, with detections out to R ~ 70 kpc.
Ibata, R, Chapman, S, Ferguson, AMN, Lewis, G, Irwin, M, Tanvir, N   +5 more
openaire   +3 more sources

Continuum Reverberation Mapping of the Accretion Disks in Two Seyfert 1 Galaxies [PDF]

The Astrophysical Journal, 2018
Abstract We present optical continuum lags for two Seyfert 1 galaxies, MCG+08-11-011 and NGC 2617, using monitoring data from a reverberation mapping campaign carried out in 2014. Our light curves span the ugriz filters over four months, with median cadences of 1.0 and 0.6 days for MCG+08-11-011 and NGC 2617, respectively, combined with ...
M. M. Fausnaugh, D. A. Starkey, Keith Horne, C. S. Kochanek, B. M. Peterson, M. C. Bentz, K. D. Denney, C. J. Grier, D. Grupe, R. W. Pogge, G. De Rosa, S. M. Adams, A. J. Barth, Thomas G. Beatty, A. Bhattacharjee, G. A. Borman, T. A. Boroson, M. C. Bottorff, Jacob E. Brown, Jonathan S. Brown, M. S. Brotherton, C. T. Coker, S. M. Crawford, K. V. Croxall, Sarah Eftekharzadeh, Michael Eracleous, M. D. Joner, C. B. Henderson, T. W.-S. Holoien, T. Hutchison, Shai Kaspi, S. Kim, Anthea L. King, Miao Li, Cassandra Lochhaas, Zhiyuan Ma, F. MacInnis, E. R. Manne-Nicholas, M. Mason, Carmen Montuori, Ana Mosquera, Dale Mudd, R. Musso, S. V. Nazarov, M. L. Nguyen, D. N. Okhmat, Christopher A. Onken, B. Ou-Yang, A. Pancoast, L. Pei, Matthew T. Penny, Radosław Poleski, Stephen Rafter, E. Romero-Colmenero, Jessie Runnoe, David J. Sand, Jaderson S. Schimoia, S. G. Sergeev, B. J. Shappee, Gregory V. Simonian, Garrett Somers, M. Spencer, Daniel J. Stevens, Jamie Tayar, T. Treu, Stefano Valenti, J. Van Saders, S. Villanueva, C. Villforth, Yaniv Weiss, H. Winkler, W. Zhu   +71 more
openaire   +6 more sources

Observational evidence for the accretion-disk origin for a radio jet in an active galaxy [PDF]

Nature, 2002
Accretion of gas onto black holes is thought to power the relativistic jets of material ejected from active galactic nuclei (AGN) and the 'microquasars' located in our Galaxy. In microquasars, superluminal radio-emitting features appear and propagate along the jet shortly after sudden decreases in the X-ray fluxes.
Marscher, Alan P., Jorstad, Svetlana G., Gomez, J. L., Aller, Margo F., Terasranta, H., Lister, M. L., Stirling, Alastair M.   +6 more
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Accretion disk versus jet orientation in H₂O megamaser galaxies [PDF]

Astronomy & Astrophysics, 2019
Context. An essential part of the paradigm describing active galactic nuclei is the alignment between the radio jet and the associated rotation axis of the sub-pc accretion disks. Because of the small linear and angular scales involved, this alignment has not yet been checked in a sufficient number of low luminosity active galactic nuclei (LLAGNs ...
Kamali, F., Henkel, C., Koyama, S., Kuo, C., Condon, J., Brunthaler, A., Reid, M., Greene, J., Menten, K., Impellizzeri, C., Braatz, J., Litzinger, E., Kadler, M.   +12 more
openaire   +3 more sources