Results 71 to 80 of about 261,296 (275)

Recoiling Black Holes: Electromagnetic Signatures, Candidates, and Astrophysical Implications

Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012
Supermassive black holes (SMBHs) may not always reside right at the centers of their host galaxies. This is a prediction of numerical relativity simulations, which imply that the newly formed single SMBH, after binary coalescence in a galaxy merger, can receive kick velocities up to several 1000 km/s due to anisotropic emission of gravitational waves ...
S. Komossa, Francesca Civano
wiley   +1 more source

Extended Narrow-Line Region in Seyfert Galaxies

Frontiers in Astronomy and Space Sciences, 2017
We present our recent results about the extended narrow-line region (ENLR) of two nearby Seyfert 2 galaxies (IC 5063 and NGC 7212) obtained by modeling the observed line profiles and spectra with composite models (photoionization+shocks) in the different
Enrico Congiu, Enrico Congiu, Marcella Contini, Stefano Ciroi, Valentina Cracco, Francesco Di Mille, Marco Berton, Marco Berton, Michele Frezzato, Giovanni La Mura, Piero Rafanelli   +10 more
doaj   +1 more source

Spectral classification of emission-line galaxies from the Sloan Digital Sky Survey. I. An improved classification for high redshift galaxies [PDF]

, 2009
We study the spectral classification of emission-line galaxies as star-forming galaxies or Active Galactic Nuclei (AGNs). From the Sloan Digital Sky Survey (SDSS) high quality data, we define an improved classification to be used for high redshift ...
Lamareille, Fabrice
core   +3 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, M. Ajello, A. Allafort, L. Baldini, J. Ballet, G. Barbiellini, D. Bastieri, K. Bechtol, R. Bellazzini, B. Berenji, E. Bloom, E. Bonamente, A. Borgland, J. Bregeon, M. Brigida, P. Bruel, R. Buehler, S. Buson, G. Caliandro, R. Cameron, P. Caraveo, J. Casandjian, E. Cavazzuti, C. Cecchi, E. Charles, A. Chekhtman, C. C. Cheung, J. Chiang, S. Ciprini, R. Claus, J. Cohen-Tanugi, J. Conrad, S. Cutini, F. D’Ammando, A. Angelis, F. Palma, C. Dermer, E. Silva, P. Drell, A. Drlica-Wagner, T. Enoto, C. Favuzzi, S. Fegan, E. Ferrara, P. Fortin, Y. Fukazawa, P. Fusco, F. Gargano, D. Gasparrini, N. Gehrels, S. Germani, N. Giglietto, P. Giommi, F. Giordano, M. Giroletti, G. Godfrey, J. Grove, S. Guiriec, D. Hadasch, M. Hayashida, E. Hays, R. Hughes, G. Jóhannesson, A. Johnson, T. Kamae, H. Katagiri, J. Kataoka, J. Knödlseder, M. Kuss, J. Lande, M. L. Garde, F. Longo, F. Loparco, B. Lott, M. Lovellette, P. Lubrano, G. Madejski, M. Mazziotta, P. Michelson, T. Mizuno, C. Monte, M. Monzani, A. Morselli, I. Moskalenko, S. Murgia, S. Nishino, J. Norris, É. Nuss, M. Ohno, T. Ohsugi, A. Okumura, E. Orlando, M. Ozaki, D. Paneque, M. Pesce-Rollins, M. Pierbattista, F. Piron, G. Pivato, T. Porter, S. Rainò, R. Rando, M. Razzano, A. Reimer, O. Reimer, S. Ritz, M. Roth, D. Sanchez, C. Sbarra, C. Sgro’, E. Siskind, G. Spandre, P. Spinelli, Ł. Stawarz, A. Strong, H. Takahashi, Tadayuki Takahashi, Takaaki Tanaka, J. Thayer, D. Thompson, L. Tibaldo, M. Tinivella, D. Torres, G. Tosti, E. Troja, Y. Uchiyama, T. Usher, J. Vandenbroucke, V. Vasileiou, G. Vianello, V. Vitale, A. Waite, B. Winer, K. Wood, M. Wood, Zhirong Yang, S. Zimmer   +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, J. F. Steiner, A. Bodaghee, P. Chakraborty, M. Sobolewska, D. R. Pasham, A. Ogorzalek, J. Zuhone, A. Bogdan, M. Vogelsberger   +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, C. Megan Urry, Francesca Civano   +2 more
wiley   +1 more source

Jetted Narrow-Line Seyfert 1 Galaxies & Co.: Where Do We Stand?

Universe, 2020
The discovery in 2008 of high-energy gamma-rays from Narrow-Line Seyfert 1 Galaxies (NLS1s) made it clear that there were active galactic nuclei (AGN) other than blazars and radio galaxies that can eject powerful relativistic jets.
Luigi Foschini
doaj   +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, Ze-Rui Wang, Ruo-Yu Liu, Junfeng Wang   +3 more
doaj   +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, Roberto Maiolino, Guido Risaliti, Isabelle Gavignaud   +3 more
wiley   +1 more source

Near-infrared spectroscopy of nearby Seyfert galaxies - II. Molecular content and coronal emission [PDF]

, 2003
We present sub-arcsec near-infrared 1.5 - 2.5 micron moderate resolution long-slit spectra of eight nearby Seyfert galaxies ...
Kotilainen, J., Prieto, M. A., Reunanen, J.   +2 more
core   +2 more sources