Results 71 to 80 of about 22,530 (230)
The far-infrared energy distributions of Seyfert and starburst galaxies in the Local Universe: ISO photometry of the 12 micron active galaxy sample [PDF]
, 2002 New far-infrared photometry with ISOPHOT, onboard the Infrared Space Observatory, is presented for 58 galaxies with homogeneous published data for another 32 galaxies all belonging to the 12 micron galaxy sample.
Alton P. B. +14 more
core +2 more sources
Microvariability in Seyfert Galaxies
The Astronomical Journal, 2003 We present the results of a search for microvariability in a sample of eight Seyfert galaxies. Microvariability (i.e., variations occurring on timescales of tens of minutes to hours) has been conclusively demonstrated to exist in the class of active galactic nuclei (AGNs) known as blazars. Its existence in other classes of AGNs is far less certain.
M. T. Carini, J. C. Noble, H. R. Miller
openaire +1 more source
Nested and Single Bars in Seyfert and Non‐Seyfert Galaxies [PDF]
The Astrophysical Journal, 2002 33 pages, including 23 postscript figures, fixed a problem with deprojected position angle profiles and the resulting bar classifications and statistics numbers and figures and tables, to appear in ...
Laine, Seppo +3 more
openaire +2 more sources
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
Optical and infrared spectrophotometry of 18 Markarian galaxies [PDF]
, 1976 Slit spectra, spectrophotometric scans and infrared broad band observations are presented. Eight of the program galaxies can be classified as Seyfert galaxies.
Becklin, E. E. +3 more
core +1 more source
ASCA observations of type-2 Seyfert Galaxies. III. Orientation and X-ray Absorption
, 1997 We discuss the spectral properties of a sample of type-2 Seyfert galaxies based upon the analysis of \asca data. In this paper we consider the sources for which the X-ray spectra appear to be dominated by the nuclear continuum, transmitted through a ...
Antonucci R. +24 more
core +1 more source
Spectral classification of emission-line galaxies from the Sloan Digital Sky Survey. I. An improved classification for high redshift galaxies [PDF]
, 2009 We study the spectral classification of emission-line galaxies as star-forming galaxies or Active Galactic Nuclei (AGNs). From the Sloan Digital Sky Survey (SDSS) high quality data, we define an improved classification to be used for high redshift ...
Lamareille, Fabrice
core +3 more sources
Mildly Suppressed Star Formation in Central Regions of MaNGA Seyfert Galaxies
, 2018 Negative feedback from accretion onto super-massive black holes (SMBHs), that is to remove gas and suppress star formation in galaxies, has been widely suggested.
Bing, Longji +10 more
core +1 more source
Markarian and Seyfert Galaxies [PDF]
Symposium - International Astronomical Union, 1999 Since this symposium is devoted to the 90th anniversary of Prof. Ambartsumian's birthday I would like to touch briefly upon some historical aspects of V. Ambartsumian's ideas on activity of nuclei of galaxies.
openaire +1 more source
The Astrophysical JournalWe 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