Results 31 to 40 of about 200 (175)

Markarian and Seyfert Galaxies [PDF]

Symposium - International Astronomical Union, 1999
Since this symposium is devoted to the 90th anniversary of Prof. Ambartsumian's birthday I would like to touch briefly upon some historical aspects of V. Ambartsumian's ideas on activity of nuclei of galaxies.
openaire   +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

Transient obscuration event captured in NGC 3227 - II. Warm absorbers and obscuration events in archival XMM-Newton and NuSTAR observations [PDF]

, 2021
International audienceThe relationship between warm absorber (WA) outflows of active galactic nuclei and nuclear obscuration activities caused by optically thick clouds (obscurers) crossing the line of sight is still unclear.
Mehdipour, M., Ciro Pinto, Costantini, E, Petrucci, P.-O., Petrucci, PO, Walton, Dominic James, Pinto, C, Walton, DJ, Di Gesu, L, Petrucci, P. -O., He, Z, Wang, Yijun, Gesu, Laura di, de Marco, Barbara, Jacobo Ebrero, Paltani, S., Di Gesu, Laura, Ehud Behar, Stéphane Paltani, Bianchi, Stefano, Ponti, G, Bianchi, S, Kriss, GA, Marco, Barbara De, Ebrero, Jacobo, Jelle Kaastra, Petrucci, Pierre-Olivier, Walton, D.J., Pinto, C., Kriss, G. A., Kaastra, J., Petrucci, P., Mao, J., He, Z., Gerard A. Kriss, Branduardi-Raymont, G, Sam Grafton-Waters, De Marco, B., Laura di Gesu, Walton, D. J., Pinto, Ciro, Xue, Y, Pierre-Olivier Petrucci, Shai Kaspi, Behar, E., Ebrero, J, Kriss, Gerard A., Kriss, G., Wang, Y., Costantini, Elisa, Gesu, L., Xue, Y., Missagh Mehdipour, Dominic James Walton, al, et, Kaspi, Shai, Marco, B., Stefano Bianchi, Paltani, Stéphane, Xue, Yongquan, Gabriele Ponti, Mehdipour, Missagh, Costantini, E., He, Zhicheng, Behar, Ehud, Ponti, Gabriele, Mao, J, Barbara De Marco, Ebrero, J., Mao, Junjie, Behar, E, Bianchi, S., Elisa Costantini, Ponti, G., Grafton-Waters, S., Kaspi, S., Wang, Y, Branduardi-Raymont, G., Kaspi, S, Paltani, S, Kaastra, J, Walton, D., De Marco, B, Graziella Branduardi-Raymont, Branduardi-Raymont, Graziella, Grafton-Waters, Sam, Kaastra, Jelle, Mehdipour, M, Grafton-Waters, S, Kriss, G.A., di Gesu, L.   +90 more
core   +1 more source

THE MID-INFRARED CONTINUA OF SEYFERT GALAXIES [PDF]

The Astrophysical Journal, 2009
25 pages, 3 tables, 11 figures; Accepted for Publication in Nov.
Deo, Rajesh. P., Richards, Gordon. T., Crenshaw, D. M., Kraemer, S. B.   +3 more
openaire   +2 more sources

Classifying Seyfert Galaxies with Deep Learning [PDF]

The Astrophysical Journal Supplement Series, 2021
Abstract The traditional classification for a subclass of the Seyfert galaxies is visual inspection or using a quantity defined as a flux ratio between the Balmer line and forbidden line. One algorithm of deep learning is the convolution neural network (CNN), which has shown successful classification results.
openaire   +2 more sources

Retrograde versus Prograde Models of Accreting Black Holes

Advances in Astronomy, Volume 2013, Issue 1, 2013., 2013
There is a general consensus that magnetic fields, accretion disks, and rotating black holes are instrumental in the generation of the most powerful sources of energy in the known universe. Nonetheless, because magnetized accretion onto rotating black holes involves both the complications of nonlinear magnetohydrodynamics that currently cannot fully be
David Garofalo, Alberto J. Castro-Tirado
wiley   +1 more source

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

, 2009
6 pages, accepted for publication in A&AInternational audienceWe study the spectral classification of emission-line galaxies as star-forming galaxies or Active Galactic Nuclei (AGNs).
F. Lamareille, Lamareille, Fabrice
core   +1 more source

Multi-wavelength campaign on NCG 7469 - IV. The broad-band X-ray spectrum [PDF]

, 2018
International audienceWe conducted a multi-wavelength 6-month campaign to observe the Seyfert Galaxy NGC 7469, using the space-based observatories HST, Swift, XMM-Newton and NuSTAR. We report the results of the spectral analysis of the seven simultaneous
E. Behar, Mehdipour, M., Costantini, E, Petrucci, P.-O., Petrucci, P-O., Di Gesu, L, Paltani, S., Ursini, F, P.-O. Petrucci, Arav, N., Ponti, G, Kriss, GA, S. Kaspi, Petrucci, Pierre-Olivier, S. Paltani, Kriss, G. A., G. A. Kriss, Kaastra, J., Petrucci, P., Mao, J., Peretz, U, Di Gesu, L., U. Peretz, De Marco, B., Middei, R., Behar, E., Peretz, U., Ebrero, J, J. Ebrero, S. Bianchi, Middei, R, Kriss, G., F. Ursini, G. Branduardi-Raymont, E. Costantini, Branduardi Raymont, G, B. De Marco, N. Arav, G. Ponti, L. Di Gesu, Petrucci, P.O., Costantini, E., J. Kaastra, Cappi, M., Mao, J, Ebrero, J., Petrucci, P-O, Behar, E, Bianchi, S., Arav, N, M. Cappi, Ponti, G., Marco, B. de, R. Middei, J. Mao, Gesu, L.Di, Kaspi, S., Branduardi-Raymont, G., Kaspi, S, Ursini, F., Cappi, M, Paltani, S, Kaastra, J, De Marco, B, Mehdipour, M, M. Mehdipour, Kriss, G.A., Branduari-Raymont, G.   +67 more
core   +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, Tommasin, Silvia, Malkan, Matthew A, Hainline, Kevin   +3 more
openaire   +3 more sources

M94 as a Unique Testbed for Black Hole Mass Estimates and AGN Activity at Low Luminosities

Advances in Astronomy, Volume 2012, Issue 1, 2012., 2012
We discuss the peculiar nature of the nucleus of M94 (NGC 4736) in the context of new measurements of the broad Hα emission from HST‐STIS observations. We show that this component is unambiguously associated with the high‐resolution X‐ray, radio, and variable UV sources detected at the optical nucleus of this galaxy.
Anca Constantin, Anil C. Seth, Antonis Georgakakis   +2 more
wiley   +1 more source