Results 51 to 60 of about 161,008 (274)

Investigating possible unification of Seyfert galaxies and blazars in Fermi-LAT sample [PDF]

, 2021
Statistical analyses are invaluable methods used to understand intrinsic emission processes and the unification of extragalactic radio sources. In this paper, we collected radio, X-ray and {\gamma}-ray data of blazars from the Fermi-LAT and Seyfert galaxies from the INTEGRAL survey and investigated the relationship between the emission properties of ...
arxiv   +1 more source

EVN observations of Seyfert galaxies [PDF]

Proceedings of The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomy and EVN Users Meeting — PoS(IX EVN Symposium), 2009
In this contribution, we report on dual-frequency EVN observations of six nuclei of Seyfert galaxies imaged previously at arcsecond resolution with the VLA. These galaxies are part of a distancelimited sample of Seyferts, for which VLBI observations are available only for the brightest objects.
Francesca Panessa, Marcello Giroletti
openaire   +3 more sources

Large-Scale Environment Properties of Narrow-Line Seyfert 1 Galaxies at z < 0.4

Frontiers in Astronomy and Space Sciences, 2017
The large-scale environment is believed to affect the evolution and intrinsic properties of galaxies. It offers a new perspective on narrow-line Seyfert 1 galaxies (NLS1) which have not been extensively studied in this context before.
Emilia Järvelä, Emilia Järvelä, A. Lähteenmäki, A. Lähteenmäki, A. Lähteenmäki, H. Lietzen   +5 more
doaj   +1 more source

Star formation in southern Seyfert galaxies [PDF]

Monthly Notices of the Royal Astronomical Society, 1998
We have produced radio maps, using the Australia Telescope Compact Array, of the central regions of six southern type 2 Seyfert galaxies (NGC 1365, 4945, 6221, 6810, 7582 and Circinus) with circumnuclear star formation, to estimate the relative contribution of star formation activity compared to activity from the active galactic nucleus (AGN).
Forbes, Duncan A., Norris, R. P.
openaire   +6 more sources

Forty Years of X-Raying Narrow-Line Seyfert 1 Galaxies

Acta Polytechnica CTU Proceedings, 2014
Forty years after the discovery of Narrow-Line Seyfert 1 Galaxies (NLS1s), and 20 years since the discovery of the remarkable ultrasoft soft X-ray emissions of NLS1s, strategic publications improved the understanding of the Seyfert phenomenon more ...
Thomas Boller
doaj   +1 more source

Spitzer/IRS 5-35 um Low-Resolution Spectroscopy of the 12 um Seyfert Sample [PDF]

, 2009
We present low-resolution 5.5-35 um spectra for 103 galaxies from the 12 um Seyfert sample, a complete unbiased 12 um flux limited sample of local Seyfert galaxies selected from the IRAS Faint Source Catalog, obtained with the Infrared Spectrograph (IRS)
Antonucci, Armus, Armus, Bassani, Bernard-Salas, Brand, Brandl, Buchanan, Calzetti, Calzetti, Charmandaris, Clavel, Cohen, Contursi, Deo, Desai, Draine, Dudley, Efstathiou, Engelbracht, Farrah, Genzel, Gorjian, Hao, Hao, Hao, Houck, Houck, Houck, Jiasheng Huang, Laurent, Le Floc'h, Luigi Spinoglio, Lutz, Maiolino, Markwardt, Meléndez, Meléndez, Nardini, Nenkova, Peeters, Sajina, Sanders, Schaerer, Shi, Shu, Silvia Tommasin, Sirocky, Smith, Spoon, Stern, Sturm, Sturm, Teplitz, Thompson, Tommasin, Vassilis Charmandaris, Voit, Weedman, Weedman, Weedman, Werner, Wu, Yan, Yanling Wu   +64 more
core   +3 more sources

Evolution of chemical abundances in Seyfert galaxies [PDF]

Astronomy & Astrophysics, 2007
17 pages, 15 figures, 3 tables, accepted for publication in A& ...
Francesco Calura, S. K. Ballero, S. K. Ballero, Francesca Matteucci, Francesca Matteucci, Paolo Padovani, Luca Ciotti   +6 more
openaire   +6 more sources

Type 2 counterparts of narrow-line Seyfert 1 galaxies [PDF]

Astrophys.J. 625 (2005) L31-L34, 2005
Unified models of Seyfert galaxies, based on viewing angles, successfully explain the observed differences between type 1 and 2 Seyferts. The existence of a range in accretion rates relative to the Eddington rate (from broad-line Seyfert 1s to narrow-line Seyfert 1s or NLS1s) and the unification of Seyfert galaxies imply that there must be type 2 ...
arxiv   +1 more source

Modelling the Multifrequency SED of AGN Candidates among the Unidentied EGRET and Fermi Gamma-Ray Sources

Acta Polytechnica CTU Proceedings, 2014
Of the 271 sources in the 3rd EGRET catalogue, 131 were reported as unidentied, i.e. not associated with any particular class of point source in the sky.
Pieter J. Meintjes, Pheneas Nkundabakura, Brian van Soelen, Alida Odendaal   +3 more
doaj   +1 more source

Growth of Accreting Supermassive Black Hole Seeds and Neutrino Radiation

Journal of Astrophysics, Volume 2015, Issue 1, 2015., 2015
In the framework of microscopic theory of black hole (MTBH), which explores the most important processes of rearrangement of vacuum state and spontaneous breaking of gravitation gauge symmetry at huge energies, we have undertaken a large series of numerical simulations with the goal to trace an evolution of the mass assembly history of 377 plausible ...
Gagik Ter-Kazarian, Gary Wegner
wiley   +1 more source