Results 81 to 90 of about 22,530 (230)
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
Galaxy Interaction and the Starburst‐Seyfert Connection [PDF]
The Astrophysical Journal, 2004 28 pages, to appear in The Astrophysical ...
Mouri, H., Taniguchi, Y.
openaire +2 more sources
A variability study of the Seyfert 2 galaxy NGC 6300 with XMM-Newton
, 2005 We present the results of timing analysis of the XMM-Newton observation of the Seyfert 2 galaxy NGC 6300. The hard X-ray spectrum above 2 keV consists of a Compton-thin-absorbed power law, as is often seen in Seyfert 2 galaxies. We clearly detected rapid
Antonucci R. R. J. +13 more
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A Composite Seyfert 2 X-ray Spectrum: Implications for the Origin of the Cosmic X-ray Background [PDF]
, 2001 We present a composite 1-10 keV Seyfert 2 X-ray spectrum, derived from ASCA observations of a distance-limited sample of nearby galaxies. All 29 observed objects were detected.
Aaron J. Barth +13 more
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Quasars around the Seyfert Galaxy NGC 3516 [PDF]
The Astrophysical Journal, 1998 We report redshift measurements of 5 X-ray emitting blue stellar objects (BSO's) located less than 12 arc min from the X-ray Seyfert galaxy, NGC 3516. We find these quasars to be distributed along the minor axis of the galaxy and to show a very good correlation between their redshift and their angular distance from NGC 3516.
Chu, Y. +4 more
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Optical Spectroscopy of the IRAS 1-Jy Sample of Ultraluminous Infrared Galaxies [PDF]
, 1999 This paper discusses the optical spectroscopic properties of the IRAS 1-Jy sample of ultraluminous infrared galaxies (ULIGs). One hundred and eight of the 118 1-Jy ULIGs have been observed at dlambda = 8.3 AA resolution over the wavelength range ~4500 A -
Allen D. A. +14 more
core +2 more sources
Chemical evolution of Seyfert galaxies [PDF]
Proceedings of the International Astronomical Union, 2007 AbstractWe computed the chemical evolution of Seyfert galaxies, residing in spiral bulges, based on an updated model for the Milky Way bulge with updated calculations of the Galactic potential and of the feedback from the central supermassive black hole (BH) in a spherical approximation. We followed the evolution of bulges of masses 2 × 109 − 1011M⊙ by
S. K. Ballero +2 more
openaire +3 more sources
An atlas of Calcium triplet spectra of active galaxies [PDF]
, 2005 We present a spectroscopic atlas of active galactic nuclei covering the region around the 8498, 8542, 8662 Calcium triplet (CaT) lines. The sample comprises 78 objects, divided into 43 Seyfert 2s, 26 Seyfert 1s, 3 Starburst and 6 normal galaxies.
Asari, N. V. +6 more
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Steep Spectrum Seyfert Galaxies
, 1996 Seyfert-type AGN that exhibit unusually strong and steep soft X-ray spectra are reviewed, building on observations made during the ROSAT all-sky survey. Two individual cases are described in brief detail, both being identified initially in the small sample of Seyferts detected in the Wide Field Camera (WFC) survey.
Pounds, K. A., Brandt, W. N.
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Symposium - International Astronomical Union, 1989 We present data for Seyfert and normal galaxies in the Revised Shapley-Ames Catalog. The type 2 Seyferts are stronger CO and Far-IR emitters (by factors of 2–4) than either normal galaxies or type 1 Seyferts. The Seyfert CO line-widths correlate with both the 21cm HI and [OIII]5007 line-widths.
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