Results 61 to 70 of about 512 (184)

The Relative Contributions of Accretion Disk versus Jet to the Optical and Mid-infrared Variability of Seyfert Galaxies

The Astrophysical Journal
We performed a comprehensive analysis of flux and color variability in a redshift-matched sample of Seyfert galaxies, comprising 23 gamma-ray-detected narrow-line Seyfert 1 galaxies (gNLS1s), 190 non-gamma-ray-detected narrow-line Seyfert 1 galaxies ...
Vineet Ojha, Xue-Bing Wu, Luis C. Ho
doaj   +1 more source

A New Sample of Gamma-Ray Emitting Jetted Active Galactic Nuclei—Preliminary Results

Universe, 2021
We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT).
Luigi Foschini, Matthew L. Lister, Sonia Antón, Marco Berton, Stefano Ciroi, Maria J. M. Marchã, Merja Tornikoski, Emilia Järvelä, Patrizia Romano, Stefano Vercellone , Elena Dalla Bontà   +10 more
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CO in Seyfert Galaxies [PDF]

Symposium - International Astronomical Union, 1989
We present data for Seyfert and normal galaxies in the Revised Shapley-Ames Catalog. The type 2 Seyferts are stronger CO and Far-IR emitters (by factors of 2–4) than either normal galaxies or type 1 Seyferts. The Seyfert CO line-widths correlate with both the 21cm HI and [OIII]5007 line-widths.
openaire   +1 more source

Effects of the environment on the properties of Seyfert galaxies [PDF]

Proceedings of the International Astronomical Union, 2004
We identify 175 Seyfert galaxies from the Southern Sky Redshift Survey - SSRS2. We use the entire SSRS2 catalog to investigate the correlation between the presence of AGN with host environment. The AGN phenomenon is more strongly correlated with the internal host properties, than with the external environment.
Maia, Marcio A. G., Willmer, Christopher N. A., Rossetto, Bruno M., Machado, Rodolfo S.   +3 more
openaire   +2 more sources

Narrow-line Seyfert 1 Galaxies in the Dark Energy Spectroscopic Instrument Data Release 1

The Astrophysical Journal Supplement Series
Narrow-line Seyfert 1 (NLSy1) galaxies are peculiar active galactic nuclei (AGN) known to exhibit a variety of intriguing observational features from low-frequency radio waves to high-energy γ -rays.
Vaidehi S. Paliya, Suvendu Rakshit, Alberto Domínguez, D. J. Saikia, C. S. Stalin   +4 more
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Spectroscopy of the galaxy components of N and Seyfert galaxies [PDF]

Publications of the Astronomical Society of the Pacific, 1987
Nuclear and off-nuclear spectra of nine active galaxies are presented. The sample consists of four Seyfert galaxies, two N galaxies, one Seyfert radio galaxy, and one liner/Seyfert 2 galaxy. All of the objects show continuum emission off the nucleus. Four clearly show absorption features from a stellar population.
Todd A. Boroson, J. B. Oke
openaire   +1 more source

Jetted Narrow-Line Seyfert 1 Galaxies & Co.: Where Do We Stand?

Universe, 2020
The discovery in 2008 of high-energy gamma-rays from Narrow-Line Seyfert 1 Galaxies (NLS1s) made it clear that there were active galactic nuclei (AGN) other than blazars and radio galaxies that can eject powerful relativistic jets.
Luigi Foschini
doaj   +1 more source

Jetted Seyfert Galaxies at z = 0: Simulating Feedback Effects on Galactic Morphology and Beyond

The Astrophysical Journal
We use high-resolution cosmological zoom-in simulations to model feedback from Seyfert-type supermassive black hole (SMBH) jets onto galaxies with identical dark matter (DM) halos of log M / M _⊙  ∼ 11.8. The low-mass,  ∼10 ^6 M _⊙ , seed SMBHs have been
Julianne Goddard, Isaac Shlosman, Emilio Romano-Diaz   +2 more
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Mid-infrared Ensemble Variability of Broad-line and Narrow-line Seyfert 1 Galaxies

The Astrophysical Journal
We utilized multiepoch archival data from the Wide-field Infrared Survey Explorer to compare the variability at 3.4 μ m (W1 band) and 4.6 μ m (W2 band) of broad-line Seyfert 1 (BLSy1) galaxies and narrow-line Seyfert 1 (NLSy1) galaxies by employing the ...
Zhipeng Hu, Lisheng Mao
doaj   +1 more source

H.E.S.S. observations of composite Seyfert–starburst galaxies

Astronomy & Astrophysics
Context. Composite galaxies that contain both Seyfert and starburst components may produce very high-energy (VHE; > 100 GeV) γ-ray emission at a wide range of spatial scales, from a few Schwarzschild radii of a supermassive black hole (SMBH; RS = 10−6 pc
Acharyya A., Aharonian F., Ashkar H., Backes M., Barbosa Martins V., Batzofin R., Becherini Y., Berge D., Böttcher M., Boisson C., Bolmont J., Borowska J., Brun F., Bruno B., Burger-Scheidlin C., Casanova S., Celic J., Cerruti M., Chandra S., Chen A., Chernyakova M., Chibueze J. O., Chibueze O., Colafrancesco S., Collins T., Cornejo B., Cotter G., Damascene Mbarubucyeye J., de Assis Scarpin J., de Bony de Lavergne M., de Naurois M., de Oña Wilhelmi E., Delgado Giler A. G., Djannati-Ataï A., Djuvsland J., Dmytriiev A., Ebrahim R., Egg K., Escañuela Nieves C., Feijen K., Filipovic M. D., Fontaine G., Funk S., Gabici S., Glicenstein J. F., Glombitza J., Goswami P., Grondin M.-H., Hess B., Hinton J. A., Holch T. L., Holler M., Horns D., Jamrozy M., Jankowsky F., Jung-Richardt I., Kasai E., Kasprzak K., Katarzyński K., Kerszberg D., Khélifi B., Komin N., Kosack K., Kostunin D., Lang R. G., Lazarević S., Lefranc V., Lenain J.-P., Liniewicz P., Luashvili A., Mackey J., Malyshev D., Malyshev D., Marandon V., Marchegiani P., Mayer M., Mehta A., Mitchell A. M. W., Moderski R., Moghadam M. O., Mohrmann L., Moulin E., Niemiec J., O’Brien P., Olivera-Nieto L., Panny S., Panter M., Parsons R. D., Pensec U., Prokhorov D. A., Pühlhofer G., Punch M., Quirrenbach A., Regeard M., Reimer A., Reimer O., Ren H., Rieger F., Rudak B., Sabri K., Sahakian V., Salzmann H., Sasaki M., Schüssler F., Shapopi J. N. S., Si Said W., Spencer S., Stawarz Ł., Steinmassl S., Tanaka T., Taylor A. M., Terrier R., Tsirou M., Unbehaun T., van Eldik C., Vecchi M., Venter C., Vink J., Wach T., Wierzcholska A., Zech A., Zhong W.   +121 more
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