Results 1 to 10 of about 385,111 (271)

Reflection in Seyfert Galaxies and the Unified Model of AGN [PDF]

, 2011
We present a deep study of the average hard X-ray spectra of Seyfert galaxies. We analyzed all public INTEGRAL IBIS/ISGRI data available on all the 165 Seyfert galaxies detected at z<0.2. Our final sample consists of 44 Seyfert 1's, 29 Seyfert 1.5's, 78 Seyfert 2's, and 14 Narrow Line Seyfert 1's.
Antonucci, Antonucci, Awaki, Barcons, Barth, Bassani, Beckmann, Beckmann, Bikmaev, Bodaghee, Brightman, Burlon, Butler, C. Ricci, Cai, Cappi, Caroli, Courvoisier, Dadina, Dadina, Della Ceca, Deluit, Deluit, Ebisawa, Eguchi, Fiore, Fiore, Gandhi, Gilli, Greenhill, Grupe, Grupe, Grupe, Grupe, Grupe, Gu, Guainazzi, Guainazzi, Guainazzi, Haardt, Haardt, Heckman, Ho, Jiménez-Bailón, Krolik, Landi, Landi, Lebrun, Longinotti, Lumsden, Magdziarz, Malizia, Malizia, Malizia, Malizia, Maoz, Maoz, Masetti, Miller, Mor, Moran, Morrison, Nagao, Narayan, Netzer, Osterbrock, Paltani, Panessa, Panessa, Pappa, Petrucci, Pfeerkorn, Pian, R. Walter, Ramos Almeida, Ramos Almeida, Rees, Ricci, Rigby, Risaliti, Risaliti, Risaliti, Risaliti, Rodriguez, Rodriguez, Rovilos, S. Paltani, Shu, T. J.-L. Courvoisier, Tomsick, Tran, Tran, Treister, Türler, Ubertini, Ueda, Veron-Cetty, Vignati, Walter, Williams, Winkler, Winter, Winter, Zdziarski, Zhang   +104 more
arxiv   +5 more sources

Seyfert Galaxies Astrophysics

Universe, 2020
Looking back in time, it is somehow surprising to see the enormous advancement made by astrophysics in just about one century [...]
Luigi Foschini
doaj   +2 more sources

The Seyfert Population in the Local Universe [PDF]

Astron.J.126:1750,2003, 2003
The magnitude-limited catalog of the Southern Sky Redshift Survey (SSRS2), is used to characterize the properties of galaxies hosting Active Galactic Nuclei. Using emission-line ratios, we identify a total of 162 (3%) Seyfert galaxies out of the parent sample with 5399 galaxies. The sample contains 121 Seyfert 2 galaxies and 41 Seyfert 1.
Christopher N. A. Willmer, Efstathiou G., Felten J. E., Kelm B., Kohler T., Kollatschny W., Laurikainen E., Laurikainen E., Maddox S. J., Maia M. A. G., Marcio A. G. Maia, Noguchi M., Petrosian A. R., Rodolfo S. Machado   +13 more
arxiv   +3 more sources

The Close Environment of Seyfert Galaxies and Its Implication for Unification Models [PDF]

, 1999
This paper presents a statistical analysis of the circumgalactic environment of nearby Seyfert galaxies based on a computer-aided search of companion galaxies on the Digitized Sky Survey (DSS). An intrinsic difference between the environment of Seyfert 1 and Seyfert 2 galaxies, suggested by previous work, is confirmed as statistically significant.
D. Dultzin-Hacyan, Dultzin-Hacyan D., Dultzin-Hacyan D., Dultzin-Hacyan D., Dultzin-Hacyan D., Gonzalez-Delgado R. M., Gu Q. S., I. Fuentes-Guridi, Laurikainen E., Laurikainen E., Lipovetsky V. A., Mas-Hesse J. M., P. Marziani, Salvato M., Shane C. D., Y. Krongold   +15 more
arxiv   +5 more sources

Morphology of Seyfert Galaxies [PDF]

, 2017
We probed the relation between properties of Seyfert nuclei and morphology of their host galaxies. We selected Seyfert galaxies from the Sloan Digital Sky Survey with redshifts less 0.2 identified by the V\'{e}ron Catalog (13th). We used the "{\it{FracDev}}" parameter from SDSS galaxy fitting models to represent the bulge fractions of the Seyfert host ...
Yen-Chen Chen, C. Hwang
arxiv   +2 more sources

On black hole masses, radio-loudness and bulge luminosities of Seyfert galaxies [PDF]

, 2001
We estimated black hole masses for 9 Seyfert 1 and 13 Seyfert 2 galaxies in the Palomar and CfA bright Seyfert samples using the tight correlation between black hole mass and bulge velocity dispersion. Combining other 13 Seyfert 1s and 2 Seyfert 2s in these samples but with black hole masses measured recently by reverberation mapping and stellar/gas ...
Adams, Begelman, Blandford, Blandford, Blundell, Boller, Boroson, Di Matteo, Dunlop, Faber, Faber, Fabian, Falcke, Falcke, Ferrarese, Ferrarese, Franceschini, Gebhardt, Gebhardt, Genzel, Ghez, Haehnelt, Haehnelt, Haiman, Ho, Ho, Ho, Ho, Ho, Huchra, Huchra, J. L. Han, Kaspi, Kaspi, Kauffmann, Kormendy, Krolik, Kukula, Kukula, Laor, Laor, Laor, Lyden-Bell, Magorrian, Mathur, Merritt, Nelson, Nelson, Osterbrock, Rees, Sadler, Sadler, Schmidt, Shakura, Silk, Simien, Véron, Wandel, Wandel, Wang, Whittle, Worthey, Xue-Bing Wu   +62 more
arxiv   +5 more sources

Soft X-ray properties of a spectroscopically selected sample of interacting and isolated Seyfert galaxies [PDF]

, 2001
We present a catalogue of ROSAT detected sources in the sample of spectroscopically selected Seyfert 1 and Seyfert 2 galaxies of Rafanelli et al. (1995). The catalogue contains 102 Seyfert 1 and 36 Seyfert 2 galaxies. The identification is based on X-ray contour maps overlaid on optical images taken from the Digitized Sky Survey.
Boller, T, Pfefferkorn, F, Rafanelli, P
arxiv   +4 more sources

Relativistic Jets in Gamma-Ray-Emitting Narrow-Line Seyfert 1 Galaxies [PDF]

Galaxies, 2019
Before the launch of the Fermi Gamma-ray Space Telescope satellite only two classes of active galactic nuclei (AGN) were known to generate relativistic jets and thus to emit up to the γ -ray energy range: blazars and radio galaxies, both hosted
Filippo D’Ammando
doaj   +2 more sources

The Multitude of Unresolved Continuum Sources at 1.6 microns in Hubble Space Telescope images of Seyfert Galaxies [PDF]

, 1999
We examine 112 Seyfert galaxies observed by the Hubble Space Telescope (HST) at 1.6 microns. We find that ~50% of the Seyfert 2.0 galaxies which are part of the Revised Shapeley-Ames (RSA) Catalog or the CfA redshift sample contain unresolved continuum sources at 1.6 microns. All but a couple of the Seyfert 1.0-1.9 galaxies display unresolved continuum
A. Alonso‐Herrero, A. C. Quillen, Alloin D., Alonso-Herrero A., Alonso-Herrero A., Antonucci R. R. J., Ariane Lee, Colleen McDonald, Fioc M., G. H. Rieke, Glass I. S., Gonzalez-Delgado R. M., Keel W. C., M. J. Rieke, Richstone D., Shanna Shaked, Terlevich R., Veron-Cetty M.-P., Wandel A.   +18 more
arxiv   +7 more sources

Dust lanes, thick absorbers, and the unification model for Seyfert galaxies [PDF]

arXiv, 2000
A modification of the popular unification model for Seyfert galaxies is proposed, which takes into account recent observational findings on the statistical properties of both type 1 and type 2 Seyferts. In the proposed scenario, Compton-thick Seyfert 2 galaxies are those sources observed through compact, thick matter (the `torus'), while Compton-thin ...
Matt, Giorgio
arxiv   +3 more sources