Results 131 to 140 of about 125,183 (220)

An automated activity classification tool for optical galaxy spectra

Astronomy & Astrophysics
Context. Reliable and versatile galaxy activity diagnostic tools are indispensable for comprehending the physical processes that drive galaxy evolution.
Daoutis C., Zezas A., Kyritsis E., Kouroumpatzakis K., Bonfini P.   +4 more
doaj   +1 more source

Seyfert galaxies and "Unified Scheme"

, 2011
From spectroscopic point of view Seyfert galaxies (as other Active Galactic Nuclei - AGN) basically are subdivided into two types: with and without broad permitted emission lines in their optical spectra (so called type I and type II Seyfert galaxies or ...
Vitrishchak, V.M., Pilipenko, S.V., Pahshchenko, I.N.   +2 more
core   +1 more source

The SRG/eROSITA all-sky survey: Hard X-ray selected active galactic nuclei

Astronomy & Astrophysics
Context. The eROSITA instrument on board the Spectrum Roentgen Gamma (SRG) satellite performed its first all-sky survey between December 2019 and June 2020.
Waddell S. G. H., Buchner J., Nandra K., Salvato M., Merloni A., Gauger I., Boller Th., Seppi R., Wolf J., Liu T., Brusa M., Comparat J., Dwelly T., Igo Z., Musiimenta B.   +14 more
doaj   +1 more source

Are “Changing-look” Active Galactic Nuclei Special in the Coevolution of Supermassive Black Holes and their Hosts? II. The Case of Changing-look Narrow-line Seyfert 1 Galaxies

The Astrophysical Journal
The evolutionary role of the so-called “changing-look” (CL) active galactic nucleus (AGN), which is characterized by spectral-type transitions within ∼10 yr, has been suggested in the past few years. By focusing on CL-AGNs having spectra similar to those
J. Wang, S. Jin, D. W. Xu, WeiKang Zheng, Thomas G. Brink, S. Komossa, Alexei V. Filippenko, J. Y. Wei   +7 more
doaj   +1 more source

Adaptive optics imaging of the nuclei of Seyfert 2 galaxies: An unexpectedly high incidence of nuclear stellar rings

Astronomy & Astrophysics
Context. The high-resolution imaging of active galactic nuclei (AGNs) on subkiloparsec scales offers an important avenue for investigating their fueling.
Mackensen N., Heidt J., Pozo Nuñez F.
doaj   +1 more source

"Velocity Dispersion and Black Hole Mass in Seyfert 1 Galaxies" [PDF]

, 2003
Paper presented at Carnegie Observatories Centennial Symposium I - Coevolution of Black Holes and Galaxies, 20-25 October 2002, Carnegie Observatories, Pasadena, CA.Bulge stellar velocity dispersions, sigma, in Seyfert 1 galaxies are combined with the ...
Green, Richard, Nelson, Charles H., Gebhardt, Karl, Bower, Gary, Weistrop, Donna   +4 more
core  

Circumnuclear molecular gas in starburst and Seyfert galaxies [PDF]

, 1990
In order to investigate circumnuclear molecular gaseous contents and their relation to the nuclear activity, researchers made a search for circumnuclear (12)CO (J=1-0) emission from 28 starburst-nucleus galaxies (SBNs) and 12 Seyfert galaxies with the ...
Kameya, Osamo, Taniguchi, Yoshiaki, Nakai, Naomasa   +2 more
core  

The Faber-Jackson relation in Seyfert galaxies

, 2007
Seyfert galaxies, in which accretion onto a massive nuclear black hole acts as a powerful energy source, allegedly have bulges more luminous per unit mass than those in normal galaxies.
Weinzirl, Timothy, Madland, Mark, Bennett, Wendy   +2 more
core  

SIFTING FOR SAPPHIRES: SYSTEMATIC SELECTION OF TIDAL DISRUPTION EVENTS IN iPTF. [PDF]

Astrophys J Suppl Ser, 2018
Hung T, Gezari S, Cenko SB, van Velzen S, Blagorodnova N, Yan L, Kulkarni SR, Lunnan R, Kupfer T, Leloudas G, Kong AKH, Nugent PE, Fremling C, Laher RR, Masci FJ, Cao Y, Roy R, Petrushevska T.   +17 more
europepmc   +1 more source

Testing The Lamp-Post and Wind Reverberation Models with XMM-Newton Observations of NGC 5506. [PDF]

Astrophys J, 2020
Zoghbi A, Kalli S, Miller JM, Mizumoto M.   +3 more
europepmc   +1 more source