Results 41 to 50 of about 34,122 (236)

Discovery of Hidden Blazars [PDF]

Science, 2001
Every radio-loud quasar may have blazar activities, according to a unified scheme where the differences in both optical and radio observations of radio-loud quasars are the result of different viewing angles. We have predicted that blazars may be detected using emission line ratio variations caused by variable illumination of gas clouds in the broad ...
Ma, Feng, Wills, Beverley J.
openaire   +3 more sources

Jet Physics of Accreting Super-Massive Black Holes in the Era of the Fermi Gamma-ray Space Telescope

Frontiers in Astronomy and Space Sciences, 2017
The Fermi Gamma-ray Space Telescope with its main instrument on-board, the Large Area Telescope (LAT), opened a new era in the study of high-energy emission from Active Galactic Nuclei (AGN).
Filippo D'Ammando, Filippo D'Ammando
doaj   +1 more source

Unveiling the nature of the unidentified gamma-ray sources III: gamma-ray blazar-like counterparts at low radio frequencies [PDF]

, 2013
About one third of the gamma-ray sources listed in the second Fermi LAT catalog (2FGL) have no firmly established counterpart at lower energies so being classified as unidentified gamma-ray sources (UGSs). Here we propose a new approach to find candidate
D'Abrusco, R., Funk, S., Giroletti, M., Masetti, N., Massaro, F., Nori, M., Paggi, A., Tosti, G.   +7 more
core   +3 more sources

Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

Frontiers in Astronomy and Space Sciences, 2017
Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert
Maialen Arrieta-Lobo, Catherine Boisson, Andreas Zech   +2 more
doaj   +1 more source

The Blazar Sequence: Validity and Predictions [PDF]

, 2006
The "blazar sequence" posits that the most powerful BL Lacertae objects and flat-spectrum radio quasars should have relatively small synchrotron peak frequencies, nu_peak, and that the least powerful such objects should have the highest nu_peak values ...
A. Caccianiga, A. Wolter, C.M. Urry, E. Nieppola, E. Pian, E.S. Perlman, G. Fossati, G. Fossati, G. Ghisellini, H. Landt, H. Landt, M.J. Collinge, P. Giommi, P. Giommi, P. Giommi, P. Giommi, P. Padovani, P. Padovani, P. Padovani, P. Padovani, P. Padovani, P. Padovani, Paolo Padovani, S. Antón   +23 more
core   +2 more sources

Asca Observations of Blazars [PDF]

Highlights of Astronomy, 1998
During the last years it has become evident that blazar class of AGN emit a lot of energy in the gamma-ray regime. It is generally thought that the non-thermal emission from blazars, observed from radio to GeV/TeV 7-rays, is radiation of very energetic particles via both synchrotron and Compton processes.
T. Takahashi, H. Kubo, G. Madejski
openaire   +1 more source

Automated Polarimetry with Smaller Aperture Telescopes: The ROVOR Observatory

Galaxies, 2017
To better understand possible blazar jet mechanisms and morphologies, brighter prototypical objects are regularly monitored for variability in optical broad-band light.
Joseph Moody, Parkes Whipple, Lauren Hindmann, Nicholas Van Alfen, Jonathan Barnes, Nicolas A. Ducharme, L. Joseph Rivest III, McKay D. Osborne, Marcus Holden, Cameron Pace, Richard L. Pearson III, Bret Little, Eric Hintz   +12 more
doaj   +1 more source

The Spectral Index Distribution of EGRET Blazars: Prospects for GLAST [PDF]

, 2007
The intrinsic distribution of spectral indices in GeV energies of gamma-ray--loud blazars is a critical input in determining the spectral shape of the unresolved blazar contribution to the diffuse extragalactic gamma-ray background, as well as an ...
Pavlidou, Vasiliki, Venters, Tonia M.
core   +4 more sources

The contribution of Fermi-2LAC blazars to the diffuse TeV-PeV neutrino flux [PDF]

, 2016
The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. One class of extragalactic sources which may produce such high-energy neutrinos are blazars.
Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., Altmann, D., Andeen, K., Anderson, T., Ansseau, I., Anton, G., Archinger, M., Arguelles, C., Argüelles, C., Arlen, T. C., Auffenberg, J., Axani, S., Bai, X., Barwick, S. W., Baum, V., Bay, R., Beatty, J. J., Becker, K. -H., BenZvi, S., Berghaus, P., Berley, D., Bernardini, E., Bernhard, A., Besson, D. Z., Binder, G., Bindig, D., Bissok, M., Blaufuss, E., Blot, S., Boersma, D. J., Bohm, C., Bos, F., Bose, D., Botner, O., Braun, J., Brayeur, L., Bretz, Hans-Peter, Burgman, A., Börner, M., Böser, S., Casey, J., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Conrad, J. M., Cowen, D. F., Daughhetee, J., Davis, J. C., Day, M., de André, J. P. A. M., De Clercq, C., De Ridder, S., de Vries, K. D., de Wasseige, G., de With, M., Dembinski, H., Desiati, P., DeYoung, T., di Lorenzo, V., Dujmovic, H., Dumm, J. P., Dunkman, M., Díaz-Vélez, J. C., Eberhardt, B., Ehrhardt, T., Eichmann, B., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., Franckowiak, A., Fuchs, T., Fösig, C. -C., Gaior, R., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glagla, M., Glüsenkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J. G., Grant, D., Griffith, Z., Góra, D., Haack, C., Hallgren, A., Halzen, F., Hansen, E., Hansmann, B., Hansmann, T., Hanson, K., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Heros, C. Pérez de los, Herrera, S. E. Sanchez, Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Holzapfel, K., Homeier, A., Hoshina, K., Huang, F., Huber, M., Huelsnitz, W., Hultqvist, K., IceCube Collaboration, IceCube Collaboration, In, S., Ishihara, A., Ismail, A. Haj, Jacobi, E., Japaridze, G. S., Jeong, M., Jero, K., Jones, B. J. P., Jurkovic, M., Kappes, A., Karg, T., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kemp, J., Kheirandish, A., Kim, M., Kintscher, T., Kiryluk, J., Kittler, T., Klein, S. R., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krings, K., Kroll, M., Krückl, G., Krüger, C., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Köpke, L., Labare, M., Lanfranchi, J. L., Larson, M. J., Lennarz, D., Lesiak-Bzdak, M., Leuermann, M., Leuner, J., Lu, L., Lünemann, J., Madsen, J., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Maunu, R., McNally, F., Meagher, K., Medici, M., Meier, M., Meli, A., Menne, T., Merino, G., Meures, T., Miarecki, S., Middell, E., Mohrmann, L., Montaruli, T., Moulai, M., Nahnhauer, R., Naumann, U., Neer, G., Niederhausen, H., Nowicki, S. C., Nygren, D. R., O'Murchadha, A., Olivas, A., Omairat, A., Palczewski, T., Pandya, H., Pankova, D. V., Penek, Ö., Pepper, J. A., Pfendner, C., Pieloth, D., Pinat, E., Pollmann, A. Obertacke, Posselt, J., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., Rameez, M., Rawlins, K., Reimann, R., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rosendo, E. del Pino, Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Rädel, L., Sabbatini, L., Sandrock, A., Sandroos, J., Sarkar, S., Satalecka, K., Schimp, M., Schlunder, P., Schmidt, T., Schoenen, S., Schumacher, L., Schöneberg, S., Schönwald, A., Seckel, D., Seunarine, S., Silva, A. H. Cruz, Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stahlberg, M., Stamatikos, M., Stanev, T., Stasik, A., Steuer, A., Stezelberger, T., Stokstad, R. G., Strotjohann, N. L., Ström, R., Stößl, A., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Ter-Antonyan, S., Terliuk, A., Tešić, G., Tilav, S., Tjus, J. Becker, Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Tselengidou, M., Turcati, A., Unger, E., Usner, M., Vallecorsa, S., van Eijndhoven, N., van Rossem, M., van Santen, J., Vandenbroucke, J., Vanheule, S., Veenkamp, J., Vehring, M., Voge, M., Vraeghe, M., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Weaver, Ch., Wendt, C., Westerhoff, S., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Wissing, H., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Zoll, M.   +322 more
core   +3 more sources

THE NATURE OF TRANSITION BLAZARS [PDF]

The Astrophysical Journal, 2014
14 pages, 11 Figures, ApJ ...
J. J. Ruan, S. F. Anderson, R. M. Plotkin, W. N. Brandt, T. H. Burnett, A. D. Myers, D. P. Schneider   +6 more
openaire   +3 more sources