ALBERT

Beschreibung: Author(s): Edgar V. Bugaev and Boris V. Mangazeev We argue that deep inelastic scattering (DIS) at small values of Q2 is an essentially nonperturbative process and can be described, partially at least, by the vector meson dominance (VMD) model. We show this by the straightforward calculation that the VMD model alone can successfully explain data on... [Phys. Rev. D 90, 014026] Published Wed Jul 16, 2014

Beschreibung: The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉VERITAS Collaboration -- VLBA 43 GHz M87 Monitoring Team -- H.E.S.S. Collaboration -- MAGIC Collaboration -- Acciari, V A -- Aliu, E -- Arlen, T -- Bautista, M -- Beilicke, M -- Benbow, W -- Bradbury, S M -- Buckley, J H -- Bugaev, V -- Butt, Y -- Byrum, K -- Cannon, A -- Celik, O -- Cesarini, A -- Chow, Y C -- Ciupik, L -- Cogan, P -- Cui, W -- Dickherber, R -- Fegan, S J -- Finley, J P -- Fortin, P -- Fortson, L -- Furniss, A -- Gall, D -- Gillanders, G H -- Grube, J -- Guenette, R -- Gyuk, G -- Hanna, D -- Holder, J -- Horan, D -- Hui, C M -- Humensky, T B -- Imran, A -- Kaaret, P -- Karlsson, N -- Kieda, D -- Kildea, J -- Konopelko, A -- Krawczynski, H -- Krennrich, F -- Lang, M J -- LeBohec, S -- Maier, G -- McCann, A -- McCutcheon, M -- Millis, J -- Moriarty, P -- Ong, R A -- Otte, A N -- Pandel, D -- Perkins, J S -- Petry, D -- Pohl, M -- Quinn, J -- Ragan, K -- Reyes, L C -- Reynolds, P T -- Roache, E -- Rose, H J -- Schroedter, M -- Sembroski, G H -- Smith, A W -- Swordy, S P -- Theiling, M -- Toner, J A -- Varlotta, A -- Vincent, S -- Wakely, S P -- Ward, J E -- Weekes, T C -- Weinstein, A -- Williams, D A -- Wissel, S -- Wood, M -- Walker, R C -- Davies, F -- Hardee, P E -- Junor, W -- Ly, C -- Aharonian, F -- Akhperjanian, A G -- Anton, G -- Barres de Almeida, U -- Bazer-Bachi, A R -- Becherini, Y -- Behera, B -- Bernlohr, K -- Bochow, A -- Boisson, C -- Bolmont, J -- Borrel, V -- Brucker, J -- Brun, F -- Brun, P -- Buhler, R -- Bulik, T -- Busching, I -- Boutelier, T -- Chadwick, P M -- Charbonnier, A -- Chaves, R C G -- Cheesebrough, A -- Chounet, L-M -- Clapson, A C -- Coignet, G -- Dalton, M -- Daniel, M K -- Davids, I D -- Degrange, B -- Deil, C -- Dickinson, H J -- Djannati-Atai, A -- Domainko, W -- Drury, L O'C -- Dubois, F -- Dubus, G -- Dyks, J -- Dyrda, M -- Egberts, K -- Emmanoulopoulos, D -- Espigat, P -- Farnier, C -- Feinstein, F -- Fiasson, A -- Forster, A -- Fontaine, G -- Fussling, M -- Gabici, S -- Gallant, Y A -- Gerard, L -- Gerbig, D -- Giebels, B -- Glicenstein, J F -- Gluck, B -- Goret, P -- Gohring, D -- Hauser, D -- Hauser, M -- Heinz, S -- Heinzelmann, G -- Henri, G -- Hermann, G -- Hinton, J A -- Hoffmann, A -- Hofmann, W -- Holleran, M -- Hoppe, S -- Horns, D -- Jacholkowska, A -- de Jager, O C -- Jahn, C -- Jung, I -- Katarzynski, K -- Katz, U -- Kaufmann, S -- Kendziorra, E -- Kerschhaggl, M -- Khangulyan, D -- Khelifi, B -- Keogh, D -- Kluzniak, W -- Kneiske, T -- Komin, Nu -- Kosack, K -- Lamanna, G -- Lenain, J-P -- Lohse, T -- Marandon, V -- Martin, J M -- Martineau-Huynh, O -- Marcowith, A -- Maurin, D -- McComb, T J L -- Medina, M C -- Moderski, R -- Moulin, E -- Naumann-Godo, M -- de Naurois, M -- Nedbal, D -- Nekrassov, D -- Nicholas, B -- Niemiec, J -- Nolan, S J -- Ohm, S -- Olive, J-F -- de Ona Wilhelmi, E -- Orford, K J -- Ostrowski, M -- Panter, M -- Paz Arribas, M -- Pedaletti, G -- Pelletier, G -- Petrucci, P-O -- Pita, S -- Puhlhofer, G -- Punch, M -- Quirrenbach, A -- Raubenheimer, B C -- Raue, M -- Rayner, S M -- Renaud, M -- Rieger, F -- Ripken, J -- Rob, L -- Rosier-Lees, S -- Rowell, G -- Rudak, B -- Rulten, C B -- Ruppel, J -- Sahakian, V -- Santangelo, A -- Schlickeiser, R -- Schock, F M -- Schroder, R -- Schwanke, U -- Schwarzburg, S -- Schwemmer, S -- Shalchi, A -- Sikora, M -- Skilton, J L -- Sol, H -- Spangler, D -- Stawarz, L -- Steenkamp, R -- Stegmann, C -- Stinzing, F -- Superina, G -- Szostek, A -- Tam, P H -- Tavernet, J-P -- Terrier, R -- Tibolla, O -- Tluczykont, M -- van Eldik, C -- Vasileiadis, G -- Venter, C -- Venter, L -- Vialle, J P -- Vincent, P -- Vivier, M -- Volk, H J -- Volpe, F -- Wagner, S J -- Ward, M -- Zdziarski, A A -- Zech, A -- Anderhub, H -- Antonelli, L A -- Antoranz, P -- Backes, M -- Baixeras, C -- Balestra, S -- Barrio, J A -- Bastieri, D -- Becerra Gonzalez, J -- Becker, J K -- Bednarek, W -- Berger, K -- Bernardini, E -- Biland, A -- Bock, R K -- Bonnoli, G -- Bordas, P -- Borla Tridon, D -- Bosch-Ramon, V -- Bose, D -- Braun, I -- Bretz, T -- Britvitch, I -- Camara, M -- Carmona, E -- Commichau, S -- Contreras, J L -- Cortina, J -- Costado, M T -- Covino, S -- Curtef, V -- Dazzi, F -- De Angelis, A -- De Cea del Pozo, E -- Delgado Mendez, C -- De los Reyes, R -- De Lotto, B -- De Maria, M -- De Sabata, F -- Dominguez, A -- Dorner, D -- Doro, M -- Elsaesser, D -- Errando, M -- Ferenc, D -- Fernandez, E -- Firpo, R -- Fonseca, M V -- Font, L -- Galante, N -- Garcia Lopez, R J -- Garczarczyk, M -- Gaug, M -- Goebel, F -- Hadasch, D -- Hayashida, M -- Herrero, A -- Hildebrand, D -- Hohne-Monch, D -- Hose, J -- Hsu, C C -- Jogler, T -- Kranich, D -- La Barbera, A -- Laille, A -- Leonardo, E -- Lindfors, E -- Lombardi, S -- Longo, F -- Lopez, M -- Lorenz, E -- Majumdar, P -- Maneva, G -- Mankuzhiyil, N -- Mannheim, K -- Maraschi, L -- Mariotti, M -- Martinez, M -- Mazin, D -- Meucci, M -- Miranda, J M -- Mirzoyan, R -- Miyamoto, H -- Moldon, J -- Moles, M -- Moralejo, A -- Nieto, D -- Nilsson, K -- Ninkovic, J -- Oya, I -- Paoletti, R -- Paredes, J M -- Pasanen, M -- Pascoli, D -- Pauss, F -- Pegna, R G -- Perez-Torres, M A -- Persic, M -- Peruzzo, L -- Prada, F -- Prandini, E -- Puchades, N -- Reichardt, I -- Rhode, W -- Ribo, M -- Rico, J -- Rissi, M -- Robert, A -- Rugamer, S -- Saggion, A -- Saito, T Y -- Salvati, M -- Sanchez-Conde, M -- Satalecka, K -- Scalzotto, V -- Scapin, V -- Schweizer, T -- Shayduk, M -- Shore, S N -- Sidro, N -- Sierpowska-Bartosik, A -- Sillanpaa, A -- Sitarek, J -- Sobczynska, D -- Spanier, F -- Stamerra, A -- Stark, L S -- Takalo, L -- Tavecchio, F -- Temnikov, P -- Tescaro, D -- Teshima, M -- Torres, D F -- Turini, N -- Vankov, H -- Wagner, R M -- Zabalza, V -- Zandanel, F -- Zanin, R -- Zapatero, J -- New York, N.Y. -- Science. 2009 Jul 24;325(5939):444-8. doi: 10.1126/science.1175406. Epub 2009 Jul 2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19574351" target="_blank"〉PubMed〈/a〉

Beschreibung: We report the detection of pulsed gamma rays from the Crab pulsar at energies above 100 giga-electron volts (GeV) with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) array of atmospheric Cherenkov telescopes. The detection cannot be explained on the basis of current pulsar models. The photon spectrum of pulsed emission between 100 mega-electron volts and 400 GeV is described by a broken power law that is statistically preferred over a power law with an exponential cutoff. It is unlikely that the observation can be explained by invoking curvature radiation as the origin of the observed gamma rays above 100 GeV. Our findings require that these gamma rays be produced more than 10 stellar radii from the neutron star.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉VERITAS Collaboration -- Aliu, E -- Arlen, T -- Aune, T -- Beilicke, M -- Benbow, W -- Bouvier, A -- Bradbury, S M -- Buckley, J H -- Bugaev, V -- Byrum, K -- Cannon, A -- Cesarini, A -- Christiansen, J L -- Ciupik, L -- Collins-Hughes, E -- Connolly, M P -- Cui, W -- Dickherber, R -- Duke, C -- Errando, M -- Falcone, A -- Finley, J P -- Finnegan, G -- Fortson, L -- Furniss, A -- Galante, N -- Gall, D -- Gibbs, K -- Gillanders, G H -- Godambe, S -- Griffin, S -- Grube, J -- Guenette, R -- Gyuk, G -- Hanna, D -- Holder, J -- Huan, H -- Hughes, G -- Hui, C M -- Humensky, T B -- Imran, A -- Kaaret, P -- Karlsson, N -- Kertzman, M -- Kieda, D -- Krawczynski, H -- Krennrich, F -- Lang, M J -- Lyutikov, M -- Madhavan, A S -- Maier, G -- Majumdar, P -- McArthur, S -- McCann, A -- McCutcheon, M -- Moriarty, P -- Mukherjee, R -- Nunez, P -- Ong, R A -- Orr, M -- Otte, A N -- Park, N -- Perkins, J S -- Pizlo, F -- Pohl, M -- Prokoph, H -- Quinn, J -- Ragan, K -- Reyes, L C -- Reynolds, P T -- Roache, E -- Rose, H J -- Ruppel, J -- Saxon, D B -- Schroedter, M -- Sembroski, G H -- Senturk, G D -- Smith, A W -- Staszak, D -- Tesic, G -- Theiling, M -- Thibadeau, S -- Tsurusaki, K -- Tyler, J -- Varlotta, A -- Vassiliev, V V -- Vincent, S -- Vivier, M -- Wakely, S P -- Ward, J E -- Weekes, T C -- Weinstein, A -- Weisgarber, T -- Williams, D A -- Zitzer, B -- New York, N.Y. -- Science. 2011 Oct 7;334(6052):69-72. doi: 10.1126/science.1208192.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21980105" target="_blank"〉PubMed〈/a〉