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Related papers: Megamaser Disks in Active Galactic Nuclei

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While 2% of active galactic nuclei (AGNs) exhibit narrow emission lines with line-of-sight velocities that are significantly offset from the velocity of the host galaxy's stars, the nature of these velocity offsets is unknown. We…

Astrophysics of Galaxies · Physics 2017-10-04 Julia M. Comerford , R. Scott Barrows , Jenny E. Greene , David Pooley

We present hydrodynamic simulations of the interstellar medium (ISM) within the circumnuclear disk (CND) of a typical AGN-dominated galaxy influenced by mechanical feedback from an active galactic nucleus(AGN). The simulations are coupled…

Investigations of H$_2$O maser galaxies at X-ray energies reveal that most AGN associated with water masers are characterized by high levels of absorption. With the aim of finding new maser sources for possible interferometric follow-ups,…

Astrophysics of Galaxies · Physics 2019-09-04 P. Castangia , G. Surcis , A. Tarchi , A. Caccianiga , P. Severgnini , R. Della Ceca

We propose that the accretion disks fueling active galactic nuclei are supported vertically against gravity by a strong toroidal ($\phi-$direction) magnetic field that develops naturally as the result of an accretion disk dynamo. The…

High Energy Astrophysical Phenomena · Physics 2016-10-12 Mitchell C. Begelman , Joseph Silk

(abridged) We present a semianalytic model of steady-state magnetically and radiatively driven disk outflows in Active Galactic Nuclei (AGNs) consisting of a continuous wind with embedded clouds. The continuous outflow is launched from the…

Astrophysics · Physics 2007-05-23 John E. Everett

An anomalous gamma-ray excess emission has been found in Fermi Large Area Telescope data covering the centre of the Galaxy. Several theories have been proposed for this `Galactic Centre Excess'. They include self-annihilation of dark matter…

High Energy Astrophysical Phenomena · Physics 2023-08-10 Oscar Macias , Chris Gordon , Roland M. Crocker , Brenna Coleman , Dylan Paterson , Shunsaku Horiuchi , Martin Pohl

The water maser in the mildly active nucleus in the nearby galaxy NGC4258 traces a thin, nearly edge-on, subparsec-scale Keplerian disk. Using the technique of very long baseline interferometry, we have detected the proper motions of these…

Active galactic nuclei present continuum and line emission. The emission lines are originated by gas located close to the central super-massive black hole. Some of these lines are broad, and would be produced in a small region called…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Anabella T. Araudo , Valenti Bosch-Ramon , Gustavo E. Romero

We show that in many methanol maser sources the masers are located in lines, with a velocity gradient along them which suggests that the masers are situated in edge-on circumstellar, or protoplanetary, disks. We present VLBI observations of…

Active galactic nuclei (AGN) are prominent environments for stellar capture, growth and formation. These environments may catalyze stellar mergers and explosive transients, such as thermonuclear and core-collapse supernovae (SNe). SN…

High Energy Astrophysical Phenomena · Physics 2021-07-13 Evgeni Grishin , Alexey Bobrick , Ryosuke Hirai , Ilya Mandel , Hagai B. Perets

Gamma and X-ray observatories have revealed spectacular structures in the emission of the tenuous hot gas surrounding the Milky Way (MW), known as the Fermi and eROSITA bubbles. Galaxy formation simulations suggest that MW-like bubbles…

Astrophysics of Galaxies · Physics 2025-04-29 Andrea Sacchi , Akos Bogdan , Nhut Truong

NGC 1068 is one of the best studied Seyfert II galaxies, for which the blackhole mass has been determined from the Doppler velocities of water maser. We show that the standard $\alpha$-disk model of NGC 1068 gives disk mass between the…

Astrophysics · Physics 2009-10-31 Pawan Kumar

As a result of their internal dynamical coherence, thin stellar streams formed by disrupting globular clusters (GCs) can act as detectors of dark matter (DM) substructure in the Galactic halo. Perturbations induced by close flybys amplify…

Astrophysics of Galaxies · Physics 2016-09-07 Nicola C. Amorisco , Facundo A. Gòmez , Simona Vegetti , Simon D. M. White

Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many,…

Astrophysics of Galaxies · Physics 2018-04-10 Tilman Hartwig , Marta Volonteri , Gohar Dashyan

Gas-rich disks in the early universe are highly turbulent and have giant star-forming clumps. Models suggest the clumps form by gravitational instabilities, and if they resist disruption by star formation, then they interact, lose angular…

Astrophysics · Physics 2009-11-13 Bruce G. Elmegreen , Frederic Bournaud , Debra Meloy Elmegreen

We analyse the 2-dimensional distribution and kinematics of the stars as well as molecular and ionised gas in the central few hundred parsecs of 5 active and 5 matched inactive galaxies. The equivalent widths of the Br-gamma line indicate…

Self-gravitating accretion disks collapse to star-forming(SF) regions extending to the inner edge of the dusty torus in active galactic nuclei (AGNs). A full set of equations including feedback of star formation is given to describe the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 J. -M. Wang , C. -S. Yan , H. -Q. Gao , C. Hu , Y. -R. Li , S. Zhang

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.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 A. Y. Wagner , M. Umemura , G. V. Bicknell

We present a study of the distribution of X-ray detected active galactic nuclei (AGN) in the five most massive, $M_{500}^{SZ}>10^{14} M_{\odot}$ , and distant, z$\sim$1, galaxy clusters in the \textit{Planck} and South Pole Telescope…

Astrophysics of Galaxies · Physics 2019-03-20 E. Koulouridis , I. Bartalucci

A relationship between the water maser detection rate and large nuclear column densities in AGN has often been cited in the literature. Indeed, detailed studies of luminous water masers, typically associated with the nuclear activity, allow…

Astrophysics of Galaxies · Physics 2016-02-03 P. Castangia , A. Tarchi , A. Caccianiga , P. Severgnini , R. Della Ceca