Results 191 to 200 of about 125,183 (220)

Unabsorbed Seyfert 2 galaxies

Astronomy and Astrophysics, 2002
We present a sample of 17 type 2 Seyfert galaxies which have an X-ray column density lower than 1022 cm-2. The Compton thin nature of these sources is strongly suggested by isotropic indicators.
Francesca Panessa, L Bassani
exaly   +2 more sources

Some of the next articles are maybe not open access.

Related searches:

HNC and HCN in Seyfert Galaxies

EAS Publications Series, 2008
What are the physical conditions in the nuclear region of Seyfert galaxies? Can we asses the predominant nuclear source of power starburst or AGN by using high density gas tracers? We have used SEST, JCMT, and IRAM 30 m telescopes to observe the J = 1 - 0, J = 3 - 2, and J = 4 - 3 transition lines of HNC and HCN in the Seyfert 2 galaxies NGC 1068 and ...
Perez-Beaupuits, J. P., Aalto, S., Spaans, M., Van der Tak, F.   +3 more
openaire   +2 more sources

Seyferts and radio galaxies

AIP Conference Proceedings, 1997
Observations with Compton Gamma Ray Observatory have provided key insights to the high energy emission mechanisms in Active Galactic Nuclei (AGN) and clearly separate them into a class of Blazars, with apparent non-thermal jet emissions often peaking in the EGRET energy band, and into the Seyfert class with emissions more closely related to the ...
W. Neil Johnson, Andrzej A. Zdziarski, Greg M. Madejski, William S. Paciesas, Helmut Steinle, Ying-Chi Lin   +5 more
openaire   +1 more source

The environment of seyfert galaxies

Chinese Astronomy and Astrophysics, 1986
Abstract We made a nearest neighbour analysis on the cluster galaxies in the CfA sample. We found that galaxies with nearest distances below 20 kpc show a clear excess of Seyfert nuclei (i.e., the incidence of Seyferts among such galaxies is about 3 times higher than the average).
null Chen Jian-sheng, null Zou Zhen-long
openaire   +1 more source

Infrared Background from Seyfert Galaxies

Nature, 1970
Kleinmann and Low1 and Low2 have recently reported measurements of the infrared spectrum of the Seyfert galaxy NGC 1068. The spectrum was found to be sharply peaked at a wavelength of ∼100 µm (with an uncertainty of a factor of two or three toward longer wavelengths), while the total infrared luminosity amounts to L∼2.5 × 1046 erg s−1 (for a Hubble ...
G, Setti, L, Woltjer
openaire   +2 more sources

Seyfert Galaxies in the Universe

1986
Recent optical spectroscopy of Seyfert galaxies, particularly at Lick Observatory, is discussed. The frame of reference is the luminosity function of Seyfert galaxies, the incompleteness of available surveys, and how complete samples can be found by combining several different types of surveys.
openaire   +1 more source

More Bars in Seyfert than in non-Seyfert Galaxies

2001
We use isophote analysis performed on near-infrared images of matched samples of Seyfert and non-active galaxies to study the overall bar fractions, and properties of the bars. We conclude that there is a small but significant excess of bars among the host galaxies of Seyferts as compared to non-Seyfert control galaxies.
Johan H. Knapen, Isaac Shlosman, Reinier F. Peletier, Seppo Laine   +3 more
openaire   +1 more source

Polycyclic aromatic hydrocarbons in Seyfert and star-forming galaxies

Monthly Notices of the Royal Astronomical Society, 2021
Almudena Alonso-Herrero, Dimitra Rigopoulou, MIGUEL Pereira Santaella   +2 more
exaly  

Chemical abundances in Seyfert galaxies – VI. Empirical abundance calibration

Monthly Notices of the Royal Astronomical Society, 2021
Oli Luiz Dors Junior
exaly  

Seyfert Galaxies

Annual Review of Astronomy and Astrophysics, 1977
openaire   +1 more source