Results 81 to 90 of about 125,183 (220)

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
doaj   +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

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

COMPTEL upper limits for Seyfert galaxies

AIP Conference Proceedings, 1994
The gamma‐ray emission of Seyfert galaxies has fallen far short of pre‐GRO expectations. No single object of this class has been detected by either COMPTEL or EGRET, and OSSE has detected only a fraction of the Seyferts expected. To derive a more stringent upper limit to the emission from these objects in the energy ranges 0.75 to 1 and 1 to 3 MeV, we ...
Maisack, M, Collmar, W, Lichti, G G, Schonfelder, V, Steinle, H, Bloemen, H, Hermsen, W, McConnell, Mark L, Stacy, G, Barr, P, Williams, O R   +10 more
openaire   +4 more sources

Seyfert Galaxies: Nuclear Radio Structure And Unification

, 2011
A radio study of a carefully selected sample of 20 Seyfert galaxies that are matched in orientation-independent parameters, which are measures of intrinsic active galactic nucleus power and host galaxy properties, is presented to test the predictions of ...
Gabuzda, Denise C, Lal, Dharam V, Shastri, Prajval, Dharam V. Lal, Denise C. Gabuzda, Prajval Shastri   +5 more
core   +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
doaj   +1 more source

Gas Motion Mapping for Three Seyfert Galaxies

Open Astronomy, 2011
We report the preliminary results of a kinematical study of three Seyfert galaxies selected from a sample of nearby active galactic nuclei observed using 3D spectroscopy.
Smirnova A., Moiseev A., Katkov I., Afanasiev V.   +3 more
doaj   +1 more source

The Impact of Seyfert Jets on Galaxy Evolution across Major Scaling Relations

The Astrophysical Journal
We analyze a suite of high-resolution cosmological zoom-in simulations of jetted Seyfert galaxies over z < ∼10 projected on the major scaling relations, comparing trajectories of “normal” versus jet-hosting galaxies. Models include thermal and mechanical
Julianne Goddard, Isaac Shlosman, Emilio Romano-Diaz   +2 more
doaj   +1 more source

The radio properties of bright Seyfert galaxies

The Astrophysical Journal Supplement Series, 1990
The radio properties of a sample of 69 bright spectroscopically selected Seyfert galaxies, which suffers from little bias toward Markarian galaxies with strong UV excess. At variance with most of the earlier results, generally based on galaxy samples which are strongly biased toward the inclusion of Markarian objects, there is no clear evidence of a ...
GIURICIN G, MARDIROSSIAN, FABIO, MEZZETTI, MARINO, BERTOTTI G.   +3 more
openaire   +2 more sources

The difference between the narrow-line regions of Seyfert 1 and Seyfert 2 galaxies [PDF]

, 1998
This paper presents a comparative study of emission-line ratios of the narrow-line regions (NLRs) of Seyfert 1 and Seyfert 2 galaxies. It includes a literature compilation of the emission-line fluxes [O II] λ3727, [Ne III] λ3869, [O III] λ5007, and [Ne V]
Schmitt, Henrique Roberto
core