Results 91 to 100 of about 367,227 (284)
HNC, HCN and CN in Seyfert galaxies [PDF]
Astronomy & Astrophysics, 2007 Accepted for publication in A&A. A selection of this paper will be presented as a poster in the FIR workshop 2007, held at Bad Honnef, Germany. High resolution figures in original paper.
Susanne Aalto +3 more
openaire +4 more sources
SEARCH FOR GAMMA-RAY EMISSION FROM X-RAY-SELECTED SEYFERT GALAXIES WITH FERMI-LAT [PDF]
, 2011 We report on a systematic investigation of the γ-ray properties of 120 hard X-ray-selected Seyfert galaxies classified as “radio-quiet” objects, utilizing the three-year accumulation of Fermi Large Area Telescope (LAT) data.
M. Ackermann +135 more
semanticscholar +1 more source
Probing extreme black‐hole outflows on short timescales via high spectral‐resolution x‐ray imagers
Astronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.Abstract We investigate outflows and the physics of super‐Eddington versus sub‐Eddington regimes in black hole systems. Our focus is on prospective science using next‐generation high‐resolution soft x‐ray instruments. We highlight the properties of black hole ultraluminous x‐ray source (ULX) systems in particular. Owing to scale invariance in accreting
C. Pinto +9 more
wiley +1 more source
The Cosmic History of Black Hole Growth from Deep Multiwavelength Surveys
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Significant progress has been made in the last few years on understanding how supermassive black holes form and grow. In this paper, we begin by reviewing the spectral signatures of active galactic nuclei (AGN) ranging from radio to hard X‐ray wavelengths.
Ezequiel Treister +2 more
wiley +1 more source
On the Hadronic Origin of High-energy Emission of γ-Ray-loud Narrow-line Seyfert 1 PKS 1502+036
The Astrophysical Journal, 2023 The radiation mechanism of Radio-Loud Narrow-Line Seyfert 1 (RL-NLS1) galaxies from X-ray to γ -ray bands remains an open question. While the leptonic model has been employed to explain the spectral energy distribution (SED), the hadronic process may ...
Zhen-Jie Wang +3 more
doaj +1 more source
IRAS observations of Seyfert galaxies [PDF]
The Astrophysical Journal, 1985 Infrared Astronomy Satellite measurements at 25, 60 and 100 microns were used to analyze the infrared properties of Seyfert galaxies from the Markarian and NGC Catalogs. One hundred and sixteen of 186 Seyfert galaxies were detected. About 50% of all Seyfert galaxies in the sample have 60 micron luminosities in excess of 10 to the 10th power solar ...
Miley, G. K. +2 more
openaire +4 more sources
A Comparison of Radio Axis with Host Galaxy Plane Axis in Seyfert Galaxies [PDF]
, 1996 We use the radio axis as an indicator of the orientation of the obscuring torus in Seyfert galaxies, and analyze the difference between the position angles of extended radio structures and host galaxy major axis of Seyfert 1 and Seyfert 2 galaxies. We find that Seyfert 1's are less likely to have extended radio structures along the host galaxy major ...
arxiv +1 more source
AGN Obscuration and the Unified Model
Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012 Unification Models of Active Galactic Nuclei postulate that all the observed differences between type 1 and type 2 objects are due to orientation effects with respect to the line of sight to the observer. The key ingredient of these models is the obscuring medium, historically envisaged as a toroidal structure on a parsec scale.
Stefano Bianchi +3 more
wiley +1 more source
Spitzer spectra of Seyfert galaxies
, 2009 to appear in the proceedings of "The Starburst-AGN Connection Conference", Shanghai, China, 27 Oct - 1 Nov 2008, ASP Conference ...
Spinoglio, Luigi +3 more
openaire +3 more sources
Are Redshifts of Seyfert Galaxies Cosmological? [PDF]
Symposium - International Astronomical Union, 1994 We have studied the Hubble diagram for an almost complete sample of 48 Seyfert galaxies. We find that if Malmquist bias is taken into account, the correlation of [log(cz), V] pairs for Seyfert galaxies is statistically significant and that the slopes of the two regression lines are consistent with those expected if the redshifts of Seyfert galaxies are
A. K. Sapre, P. S. Parihar
openaire +2 more sources