Insights into the high-energy γ-ray emission of Markarian 501 from extensive multifrequency observations in the Fermi era

Journal
Date Issued
2011
Author(s)
Abdo, A.A.
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Ackermann, M.
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Ajello, M.
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Allafort, A.
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Baldini, L.
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Ballet, J.
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Barbiellini, G.
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Baring, M.G.
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Bastieri, D.
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Bechtol, K.
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Bellazzini, R.
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Mizuno, T.
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Moiseev, A.A.
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Monte, C.
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Monzani, M.E.
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Morselli, A.
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Moskalenko, I.V.
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Murgia, S.
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Naumann-Godo, M.
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Nishino, S.
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Nolan, P.L.
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Berenji, B.
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Norris, J.P.
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Nuss, E.
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Ohsugi, T.
•
Okumura, A.
•
Omodei, N.
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Orlando, E.
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Ormes, J.F.
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Paneque, D.
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Panetta, J.H.
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Parent, D.
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Blandford, R.D.
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Pavlidou, V.
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Pearson, T.J.
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Pelassa, V.
•
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Pesce-Rollins, M.
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Piron, F.
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Porter, T.A.
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Rainò, S.
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Rando, R.
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Razzano, M.
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Bloom, E.D.
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Readhead, A.
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Reimer, A.
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Reimer, O.
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Richards, J.L.
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Ripken, J.
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Ritz, S.
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Roth, M.
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Sadrozinski, H.F.-W.
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Sanchez, D.
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Sander, A.
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Bonamente, E.
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Scargle, J.D.
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Sgrò, C.
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Siskind, E.J.
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Smith, P.D.
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Spandre, G.
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Spinelli, P.
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Stawarz, L.
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Stevenson, M.
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Strickm, M.S.
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Sokolovsky, K.V.
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Borgland, A.W.
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Suson, D.J.
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Takahashi, H.
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Takahashi, T.
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Tanaka, T.
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Thayer, J.B.
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Thayer, J.G.
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Thompson, D.J.
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Tibaldo, L.
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Torres, D.F.
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Tosti, G.
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Bouvier, A.
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Tramacere, A.
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Uchiyama, Y.
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Usher, T.L.
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Vandenbroucke, J.
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Vasileiou, V.
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Vilchez, N.
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Vitale, V.
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Waite, A.P.
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Wang, P.
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Wehrle, A.E.
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Brandt, T.J.
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Winer, B.L.
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Wood, K.S.
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Yang, Z.
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Ylinen, T.
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Zensus, J.A.
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Ziegler, M.
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Aleksić, J.
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Antoranz, P.
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Backes, M.
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Bregeon, J.
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Barrio, J.A.
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González, J.B.
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Bednarek, W.
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Berdyugin, A.
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Berger, K.
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Bernardini, E.
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Biland, A.
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Blanch, O.
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Bock, R.K.
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Boller, A.
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Brez, A.
•
•
Bordas, P.
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Tridon, D.B.
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Bosch-Ramon, V.
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Bose, D.
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Braun, I.
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Bretz, T.
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Camara, M.
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Carmona, E.
•
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Brigida, M.
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Colin, P.
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Colombo, E.
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Contreras, J.L.
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Cortina, J.
•
•
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De Angelis, A.
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De Cea Del Pozo, E.
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De Lotto, B.
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De Maria, M.
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Bruel, P.
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De Sabata, F.
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Delgado Mendez, C.
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Diago Ortega, A.
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Doert, M.
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Domínguez, A.
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Prester, D.D.
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Dorner, D.
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Doro, M.
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Elsaesser, D.
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Ferenc, D.
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Buehler, R.
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Fonseca, M.V.
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Font, L.
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López, R.J.G.
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Garczarczyk, M.
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Gaug, M.
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Giavitto, G.
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Godinovi, N.
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Hadasch, D.
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Herrero, A.
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Hildebrand, D.
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Buson, S.
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Höhne-Mönch, D.
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Hose, J.
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Hrupec, D.
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Jogler, T.
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Klepser, S.
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Krähenbühl, T.
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Kranich, D.
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Krause, J.
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Leonardo, E.
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Caliandro, G.A.
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Lindfors, E.
•
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López, M.
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Lorenz, E.
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Majumdar, P.
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Makariev, E.
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Maneva, G.
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Mankuzhiyil, N.
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Mannheim, K.
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Maraschi, L.
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Cameron, R.A.
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Mariotti, M.
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Martínez, M.
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Mazin, D.
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Meucci, M.
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Miranda, J.M.
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Mirzoyan, R.
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Miyamoto, H.
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Moldón, J.
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Moralejo, A.
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Nieto, D.
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Cannon, A.
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Nilsson, K.
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Orito, R.
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Oya, I.
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Paoletti, R.
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Paredes, J.M.
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Partini, S.
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Pasanen, M.
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Pauss, F.
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Pegna, R.G.
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Perez-Torres, M.A.
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Caraveo, P.A.
•
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Peruzzo, J.
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Pochon, J.
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Prada Moroni, P.G.
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Prada, F.
•
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Puchades, N.
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Puljak, I.
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Reichardt, T.
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Reinthal, R.
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Carrigan, S.
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Rhode, W.
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Ribó, M.
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Rico, J.
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Rissi, M.
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Rügamer, S.
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Saggion, A.
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Saito, K.
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Saito, T.Y.
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Salvati, M.
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Sánchez-Conde, M.
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Casandjian, J.M.
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Satalecka, K.
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Scalzotto, V.
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Scapin, V.
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Schultz, C.
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Schweizer, T.
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Shayduk, M.
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Shore, S.N.
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Sierpowska-Bartosik, A.
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Sillanpää, A.
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Sitarek, J.
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Cavazzuti, E.
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Sobczynska, D.
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Spanier, F.
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Spiro, S.
•
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Steinke, B.
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Storz, J.
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Strah, N.
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Struebig, J.C.
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Suric, T.
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Takalo, L.O.
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Cecchi, C.
•
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Temnikov, P.
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Terzić, T.
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Tescaro, D.
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Teshima, M.
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Vankov, H.
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Wagner, R.M.
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Weitzel, Q.
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Zabalza, V.
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Zandanel, F.
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Çelik, Ö.
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Zanin, R.
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Acciari, V.A.
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Arlen, T.
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Aune, T.
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Benbow, W.
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Boltuch, D.
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Bradbury, S.M.
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Buckley, J.H.
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Bugaev, V.
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Cannon, A.
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Charles, E.
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Cesarini, A.
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Ciupik, L.
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Cui, W.
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Dickherber, R.
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Errando, M.
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Falcone, A.
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Finley, J.P.
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Finnegan, G.
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Fortson, L.
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Furniss, A.
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Chekhtman, A.
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Galante, N.
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Gall, D.
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Gillanders, G.H.
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Godambe, S.
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Grube, J.
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Guenette, R.
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Gyuk, G.
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Hanna, D.
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Holder, J.
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Huang, D.
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Cheung, C.C.
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Hui, C.M.
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Humensky, T.B.
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Kaaret, P.
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Karlsson, N.
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Kertzman, M.
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Kieda, D.
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Konopelko, A.
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Krawczynski, H.
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Krennrich, F.
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Lang, M.J.
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Chiang, J.
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Maier, G.
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McArthur, S.
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McCann, A.
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McCutcheon, M.
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Moriarty, P.
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Mukherjee, R.
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Ong, R.
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Otte, A.N.
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Pandel, D.
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Perkins, J.S.
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Ciprini, S.
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Pichel, A.
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Pohl, M.
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Quinn, J.
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Ragan, K.
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Reyes, L.C.
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Reynolds, P.T.
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Roache, E.
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Rose, H.J.
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Rovero, A.C.
•
Schroedter, M.
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Claus, R.
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Sembroski, G.H.
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Senturk, G.D.
•
Steele, D.
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Swordy, S.P.
•
Tešić, G.
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Theiling, M.
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Thibadeau, S.
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Varlotta, A.
•
Vincent, S.
•
Wakely, S.P.
•
Cohen-Tanugi, J.
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Ward, J.E.
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Weekes, T.C.
•
Weinstein, A.
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Weisgarber, T.
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Williams, D.A.
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Wood, M.
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Zitzer, B.
•
•
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Aller, H.D.
•
Conrad, J.
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Aller, M.F.
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Arkharov, A.A.
•
Blinov, D.A.
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Calcidese, P.
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Chen, W.P.
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Efimova, N.V.
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Kimeridze, G.
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Konstantinova, T.S.
•
Kopatskaya, E.N.
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Koptelova, E.
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Cutini, S.
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Kurtanidze, O.M.
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Kurtanidze, S.O.
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Lähteenmäki, A.
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Larionov, V.M.
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Larionova, E.G.
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Larionova, L.V.
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Ligustri, R.
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Morozova, D.A.
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Nikolashvili, M.G.
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Sigua, L.A.
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Dermer, C.D.
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Troitsky, I.S.
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Angelakis, E.
•
•
Carramiñana, A.
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Carrasco, L.
•
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De La Fuente, E.
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Gurwell, M.A.
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Kovalev, Y.Y.
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Kovalev, Yu.A.
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De Palma, F.
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Krichbaum, T.P.
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Krimm, H.A.
•
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Lister, M.L.
•
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Moody, J.W.
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Mori, Y.
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Nestoras, I.
•
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Pagani, C.
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Do Couto E Silva, E.
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Pace, C.
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Pearson III, R.
•
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Piner, B.G.
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Pushkarev, A.B.
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Ros, E.
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Sadun, A.C.
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Sakamoto, T.
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Tornikoski, M.
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Yatsu, Y.
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Drell, P.S.
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Zook, A.
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Dubois, R.
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Dumora, D.
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Favuzzi, C.
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Fegan, S.J.
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Ferrara, E.C.
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Focke, W.B.
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Fortin, P.
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Fuhrmann, L.
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Fukazawa, Y.
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Funk, S.
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Fusco, P.
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Gargano, F.
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Gasparrini, D.
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Gehrels, N.
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Germani, S.
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Giglietto, N.
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Giordano, F.
•
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Glanzman, T.
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Godfrey, G.
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Grenier, I.A.
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Guillemot, L.
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Guiriec, S.
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Hayashida, M.
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Hays, E.
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Horan, D.
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Hughes, R.E.
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Jóhannesson, G.
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Johnson, A.S.
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Johnson, W.N.
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Kadler, M.
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Kamae, T.
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Katagiri, H.
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Kataoka, J.
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Knödlseder, J.
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Kuss, M.
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Lande, J.
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Latronico, L.
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Lee, S.-H.
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Lemoine-Goumard, M.
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Longo, F.
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Loparco, F.
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Lott, B.
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Lovellette, M.N.
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Lubrano, P.
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Madejski, G.M.
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Makeev, A.
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Max-Moerbeck, W.
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Mazziotta, M.N.
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McEnery, J.E.
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Mehault, J.
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Michelson, P.F.
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Mitthumsiri, W.
DOI
Abstract
We report on the γ-ray activity of the blazar Mrk 501 during the first 480 days of Fermi operation. We find that the average Large Area Telescope (LAT) γ-ray spectrum of Mrk 501 can be well described by a single power-law function with a photon index of 1.78 ± 0.03. While we observe relatively mild flux variations with the Fermi-LAT (within less than a factor of two), we detect remarkable spectral variability where the hardest observed spectral index within the LAT energy range is 1.52 ± 0.14, and the softest one is 2.51 ± 0.20. These unexpected spectral changes do not correlate with the measured flux variations above 0.3 GeV. In this paper, we also present the first results from the 4.5 month long multifrequency campaign (2009 March 15-August 1) on Mrk 501, which included the Very Long Baseline Array (VLBA), Swift, RXTE, MAGIC, and VERITAS, the F-GAMMA, GASP-WEBT, and other collaborations and instruments which provided excellent temporal and energy coverage of the source throughout the entire campaign. The extensive radio to TeV data set from this campaign provides us with the most detailed spectral energy distribution yet collected for this source during its relatively low activity. The average spectral energy distribution of Mrk 501 is well described by the standard one-zone synchrotron self-Compton (SSC) model. In the framework of this model, we find that the dominant emission region is characterized by a size ≲0.1 pc (comparable within a factor of few to the size of the partially resolved VLBA core at 15-43 GHz), and that the total jet power (≃1044 erg s-1) constitutes only a small fraction (∼10-3) of the Eddington luminosity. The energy distribution of the freshly accelerated radiating electrons required to fit the time-averaged data has a broken power-law form in the energy range 0.3 GeV-10 TeV, with spectral indices 2.2 and 2.7 below and above the break energy of 20 GeV. We argue that such a form is consistent with a scenario in which the bulk of the energy dissipation within the dominant emission zone of Mrk 501 is due to relativistic, proton-mediated shocks. We find that the ultrarelativistic electrons and mildly relativistic protons within the blazar zone, if comparable in number, are in approximate energy equipartition, with their energy dominating the jet magnetic field energy by about two orders of magnitude. © 2011. The American Astronomical Society.
Volume
727
Issue
2
Start page
129
Uri
Url
Issn Identifier
0004-637X
Ads BibCode
2011ApJ...727..129A
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open.access
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