Results 1 to 10 of about 261,296 (275)

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

Origin of X-ray Spectral Variation and the Seemingly Broad Iron-Line Spectral Feature in Seyfert Galaxies

Acta Polytechnica CTU Proceedings, 2014
We present systematic X-ray data analysis of the Seyfert galaxies observed by Suzaku to study origin of their hard X-ray (2 - 40 keV) variations. In particular, we examine if the "Variable Partial Covering (VPC) model" proposed by Miyakawa, Ebisawa and ...
Ken Ebisawa, Naoki Iso, Takehiro Miyakawa, Hajime Inoue   +3 more
doaj   +3 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

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 z200keV, and a photon index of Gamma ~1.8.
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
core   +2 more sources

X-ray spectral properties of Seyfert galaxies and the unification scheme [PDF]

, 2011
Aims: The unification scheme of Seyfert galaxies predicts that the observed differences between type 1 and type 2 Seyfert galaxies are solely due to the differing orientations of the toroidal-shaped obscuring material around AGN.
Akylas, Antonucci, Antonucci, Awaki, Awaki, Awaki, Awaki, Bassani, Beckmann, Bianchi, Bianchi, Bianchi, Blustin, Blustin, Braito, Buchanan, Cappi, Cardamone, Cid Fernandes, Dadina, Dahari, De Rosa, Ferruit, G. Risaliti, Gallagher, Ghisellini, Ghisellini, Gilli, González Delgado, Grandi, Griffiths, Guainazzi, Guainazzi, Heckman, Heckman, Ho, Kellermann, King, Kinkhabwala, Krolik, Lal, Leahy, Leighly, Levenson, Levenson, Levenson, Magdziarz, Maiolino, Maiolino, Malkan, Mason, Mateos, Matt, Matt, Matt, Matt, Miller, Moran, Mulchaey, Mulchaey, Nandra, Nandra, Nelson, P. Shastri, Panessa, Panessa, Perola, Piro, Polletta, Pounds, Ptak, Reynolds, Risaliti, Sako, Sambruna, Schmidt, Schmitt, Schurch, Schurch, Smith, Terashima, Tran, Tran, Treister, Tueller, Turner, Turner, Turner, Urry, V. Singh, Vignali, Wang, Weaver, Weaver, Weedman, Whittle, Worsley, Yang, Yee, Young   +99 more
core   +2 more sources

High-energy Neutrinos from Magnetized Coronae of Active Galactic Nuclei and Prospects for Identification of Seyfert Galaxies and Quasars in Neutrino Telescopes [PDF]

Astrophysical Journal, 2021
Particles may be accelerated in magnetized coronae via magnetic reconnections and/or plasma turbulence, leading to high-energy neutrinos and soft γ-rays.
A. Kheirandish, K. Murase, S. Kimura
semanticscholar   +1 more source

Studying the Correlation Between Supermassive Black Holes and Star Formation Rate for Samples of Seyfert Galaxies (Type 1 and 2)

Iraqi Journal of Physics, 2021
An optical spectroscopic study is reported in this article to study the correlation between the supermassive black hole (SMBH) and the star formation rate (SFR) for a sample of Seyfert galaxies type (I and II).
Salwa H. Kareem, Yasir Ezzuldeen Rashed
doaj   +1 more source

Estimate of SMBH Spin for Narrow-Line Seyfert 1 Galaxies

Universe, 2023
We estimated the spin values of the supermassive black holes (SMBHs) of the active galactic nuclei (AGN) for a large set of Narrow Line Seyfert 1 (NLS1) galaxies assuming the inclination angle between the line of sight and the axis of the accretion disk ...
Mikhail Piotrovich, Stanislava Buliga, Tinatin Natsvlishvili   +2 more
doaj   +1 more source

A radio polarimetric study to disentangle AGN activity and star formation in Seyfert galaxies [PDF]

, 2020
To understand the origin of radio emission in radio-quiet AGN and differentiate between the contributions from star formation, AGN accretion, and jets, we have observed a nearby sample of Seyfert galaxies along with a comparison sample of starburst ...
B. Sebastian, Preeti Kharb, C. O’Dea, J. Gallimore, S. Baum   +4 more
semanticscholar   +1 more source

A NuSTAR census of coronal parameters in Seyfert galaxies [PDF]

Astronomy & Astrophysics, 2018
Context. We discuss the results of the hot corona parameters of active galactic nuclei (AGN) that have been recently measured with NuSTAR. The values taken from the literature of a sample of 19 bright Seyfert galaxies are analysed. Aims.
A. Tortosa, S. Bianchi, A. Marinucci, G. Matt, O. Petrucci   +4 more
semanticscholar   +1 more source