Results 131 to 140 of about 22,530 (230)

Soft gamma rays from low accreting supermassive black holes and connection to energetic neutrinos. [PDF]

Nat Commun, 2021
Kimura SS, Murase K, Mészáros P.
europepmc   +1 more source

The Disk Wind Contribution to the Gamma-Ray Emission from the Nearby Seyfert Galaxy GRS 1734−292

The Astrophysical Journal
Radio-quiet Seyfert galaxies have been detected in GeV gamma rays by the Fermi Large Area Telescope (LAT), but the origin of much of this emission is unclear.
Nobuyuki Sakai, Tomoya Yamada, Yoshiyuki Inoue, Ellis R. Owen, Tomonari Michiyama, Ryota Tomaru, Yasushi Fukazawa   +6 more
doaj   +1 more source

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

On the Role of Minor Galaxy Mergers in the Formation of Active Galactic Nuclei

, 2000
The large scale (~ 100 kpc) environments of Seyfert galaxies are not significantly different from those of non-Seyfert galaxies. In the context of the interaction model of the formation of active galactic nuclei (AGN), it has been proposed that AGN form ...
Genzel R., Laurikainen E., Michael R. Corbin, Petrosian A. R.   +3 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

Reverberation mapping of active galactic nuclei: from X-ray corona to dusty torus. [PDF]

iScience, 2021
Cackett EM, Bentz MC, Kara E.
europepmc   +1 more source

Unification Model of Seyfert Galaxies: Are All Seyfert 2 Galaxies Created Equal?

, 2002
2 pages, 2 figures to be published in the proceedings of "Active Galactic Nuclei: From Central Engine to Host Galaxy", Meudon, France, 23-27 July, 2002, ASP Conference Series, Eds. S. Collin, F.
openaire   +2 more sources

Anomalous Narrow Line Seyfert I Galaxies from SDSS DR17

The Astrophysical Journal
We present an analysis of 22,656 narrow-line Seyfert 1 galaxies (NLSy1s) from the Sloan Digital Sky Survey (SDSS) DR17 (0.1 ≤ z ≤ 0.9), identifying a sample of spectroscopically anomalous sources.
Arihant Tiwari, Rachana, M. Vivek, Suvendu Rakshit   +3 more
doaj   +1 more source

RAD@home Citizen Science Discovery of Two Spiral Galaxies Where the 30–220 kpc Radio Lobes Are Possibly Shaped by Ram Pressure Stripping

Galaxies
We report the RAD@home citizen science discovery of two rare spiral-host radio galaxies (NGC 3898 and WISEA J221656.57-132042434.1 or RAD-“Thumbs up” galaxy), both exhibiting asymmetric radio lobes extending over 30 to 220 kiloparsec scales. We present a
Prakash Apoorva, Ananda Hota, Pratik Dabhade, P. K. Navaneeth, Dhruv Nayak, Arundhati Purohit   +5 more
doaj   +1 more source

X-ray spectral properties of Seyfert galaxies and the unification scheme

, 2011
Aims: The unification scheme of Seyfert galaxies predicts that the observed differences between type 1 and type 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN.
Akylas, Antonucci, Antonucci, Awaki, Awaki, Awaki, Awaki, Bassani, Beckmann, Bianchi, Bianchi, Bianchi, Blustin, Blustin, Braito, Buchanan, Cappi, Cardamone, Cid Fernandes, Dadina, Dahari, De Rosa, Ferruit, G. Risaliti, Gallagher, Ghisellini, Ghisellini, Gilli, González Delgado, Grandi, Griffiths, Guainazzi, Guainazzi, Heckman, Heckman, Ho, Kellermann, King, Kinkhabwala, Krolik, Lal, Leahy, Leighly, Levenson, Levenson, Levenson, Magdziarz, Maiolino, Maiolino, Malkan, Mason, Mateos, Matt, Matt, Matt, Matt, Miller, Moran, Mulchaey, Mulchaey, Nandra, Nandra, Nelson, P. Shastri, Panessa, Panessa, Perola, Piro, Polletta, Pounds, Ptak, Reynolds, Risaliti, Sako, Sambruna, Schmidt, Schmitt, Schurch, Schurch, Smith, Terashima, Tran, Tran, Treister, Tueller, Turner, Turner, Turner, Urry, V. Singh, Vignali, Wang, Weaver, Weaver, Weedman, Whittle, Worsley, Yang, Yee, Young   +99 more
core   +1 more source