Results 121 to 130 of about 261,296 (275)

IRAS observations of active galaxies [PDF]

, 1986
The IRAS survey gives an unbiased view of the infrared properties of the active galaxies. Seyfert galaxies occupy much the same area in color-color plots as to normal infrared bright galaxies, but extend the range towards flatter 60 to 25 mm slopes ...
AR Sandage, BT Soifer, DJ Ennis, EJ Wampler, G Neugebauer, G Neugebauer, JJ Condon, KI Kellermann, MP Veron-Cetty, PE Clegg, T Gehren, TA Boroson   +11 more
core   +2 more sources

Modeling Star Formation Histories of Changing-look AGN Host Galaxies with Prospector

The Astrophysical Journal
Changing-look active galactic nuclei (CL-AGNs), are AGNs that appear to transition between Seyfert Type 1 and 2 over periods of months to years. Several mechanisms to trigger these transitions have been proposed, but we have yet to conclusively determine
Margaret E. Verrico, K. Decker French, Katherine A. Suess, Tanay Agrawal, Lauranne Lanz, Yuanze Luo, Pallavi Patil, Kate Rowlands, Margaret Shepherd, Maya Skarbinski   +9 more
doaj   +1 more source

A MULTI-WAVELENGTH STUDY OF THE NATURE OF TYPE 1.8/1.9 SEYFERT GALAXIES [PDF]

, 2010
We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type 1.8 or 1.9. Are these “intermediate” Seyfert types typical Seyfert 1 nuclei with reddened broad-line regions?
M. Trippe, D. Crenshaw, R. Deo, M. Dietrich, S. Kraemer, S. Kraemer, S. Rafter, T. Turner   +7 more
semanticscholar   +1 more source

The hard X-ray view of bright infrared galaxies

, 2009
Aims. The synthesis of the cosmic X-ray background (CXB) requires a large population of Compton-thick active galactic nuclei that have not been detected so far.
Akylas, Armus, Barger, Bassani, Courvoisier, Dadina, de Rosa, Franceschini, Genzel, Gilli, Gondoin, González-Martín, Grimm, Guainazzi, Kawakatu, Kennicutt, La Franca, Lebrun, Lynden-Bell, Matt, Mushotzky, N. Cabral, Paltani, R. Walter, Risaliti, Risaliti, Sanders, Schmidt, Setti, Terashima, Tozzi, Tueller, Ubertini, Vega, Vignati, Walter, Watabe, Wilkes, Wilkes, Zdziarski   +39 more
core   +1 more source

Free-Free Absorption and the Unified Scheme [PDF]

, 2003
We report Very-Long-Baseline Array (VLBA) observations at 2.3, 8.4, and 15.4 GHz towards nine GHz-Peaked Spectrum (GPS) sources. One Seyfert 1 galaxy, one Seyfert 2 galaxy, three radio galaxies, and four quasars were included in our survey.
Carvalho, de Vries, Kameno, Kameno, Kiyoaki Wajima, Makoto Inoue, Saikia, Satoko Sawada-Satoh, Seiji Kameno, Zhi-Qiang Shen   +9 more
core   +3 more sources

Correlations between environmental parameters and nuclear activity [PDF]

The occurrence and quantitative properties of Seyfert 1 and Seyfert 2 galaxies as a function of the galaxy environment were studied in a systematic way.
Fricke, K. J., Kollatschny, W.
core   +1 more source

On Core Collapse Supernovae in Normal and in Seyfert Galaxies [PDF]

, 2002
This paper estimates the relative frequency of different types of core-collapse supernovae, in terms of the ratio f between the number of type Ib--Ic and of type II supernovae.
Bressan, A., Della Valle, M., Marziani, P.   +2 more
core   +2 more sources

Intensive Broadband Reverberation Mapping of Fairall 9 with 1.8 yr of Daily Swift Monitoring

The Astrophysical Journal
We present 1.8 yr of near-daily Swift monitoring of the bright, strongly variable Type 1 active galactic nucleus (AGN) Fairall 9. Totaling 575 successful visits, this is the largest such campaign reported to date.
R. Edelson, B. M. Peterson, J. Gelbord, K. Horne, M. Goad, I. McHardy, S. Vaughan, M. Vestergaard   +7 more
doaj   +1 more source

Mapping the Narrow-Line Seyfert 1 Galaxy 1H 0323+342

Universe, 2019
Taking advantage of the most recent measurements by means of high-resolution radio observations and other multiwavelength campaigns, it is possible to elaborate a detailed map of the narrow-line Seyfert 1 Galaxy 1H 0323 + 342 .
Luigi Foschini, Stefano Ciroi, Marco Berton, Stefano Vercellone, Patrizia Romano, Valentina Braito   +5 more
doaj   +1 more source

Modeling Cosmological Evolution of Jetted Seyfert Galaxies for z ≲ 10

The Astrophysical Journal
We use high-resolution cosmological zoom-in simulations to model mechanical and thermal feedback from active galactic nuclei onto the evolution of Seyfert-type galaxies, studying the morphology of central galaxies growing within dark matter (DM) halos ...
Julianne Goddard, Isaac Shlosman, Emilio Romano-Diaz   +2 more
doaj   +1 more source