Contemporaneous observations of the radio galaxy NGC 1275 from radio to very high energy gamma-rays
: Aleksic J, Ansoldi S, Antonelli LA, Antoranz P, Babic A, Bangale P, de Almeida UB, Barrio JA, Gonzalez JB, Bednarek W, Berger K, Bernardini E, Biland A, Blanch O, Bock RK, Bonnefoy S, Bonnoli G, Borracci F, Bretz T, Carmona E, Carosi A, Fidalgo DC, Colin P, Colombo F, Contreras JL, Cortina J, Covino S, Da Vela P, Dazzi F, De Angelis A, De Caneva G, De Lotto B, Mendez CD, Doert M, Dominguez A, Prester DD, Dorner D, Doro M, Einecke S, Eisenacher D, Elsaesser D, Farina E, Ferenc D, Fonseca MV, Font L, Frantzen K, Fruck C, Lopez RJG, Garczarczyk M, Terrats DG, Gaug M, Giavitto G, Godinovic N, Munoz AG, Gozzini SR, Hadamek A, Hadasch D, Herrero A, Hildebrand D, Hose J, Hrupec D, Idec W, Kadenius V, Kellermann H, Knoetig ML, Krause J, Kushida J, La Barbera A, Lelas D, Lewandowska N, Lindfors E, Lombardi S, Lopez M, Lopez-Coto R, Lopez-Oramas A, Lorenz F, Lozano I, Makariev M, Mallot K, Maneva G, Mankuzhiyil N, Mannheim K, Maraschi L, Marcote B, Mariotti M, Martinez M, Mazin D, Menzel U, Meucci M, Miranda JM, Mirzoyan R, Moralejo A, Munar-Adrover P, Nakajima D, Niedzwiecki A, Nilsson K, Nowak N, Orito R, Overkemping A, Paiano S, Palatiello M, Paneque D, Paoletti R, Paredes JM, Paredes-Fortuny X, Partini S, Persic M, Prada F, Moroni PGP, Prandini E, Preziuso S, Puljak I, Reinthal R, Rhode W, Ribo M, Rico J, Garcia JR, Rugamer S, Saggion A, Saito T, Saito K, Salvati M, Satalecka K, Scalzotto V, Scapin V, Schultz C, Schweizer T, Shore SN, Sillanpaa A, Sitarek J, Snidaric I, Sobczynska D, Spanier F, Stamatescu V, Stamerra A, Steinbring T, Storz J, Sun S, Suric T, Takalo L, Tavecchio F, Terzic T, Tescaro D, Teshima M, Thaele J, Tibolla O, Torres DF, Toyama T, Treves A, Uellenbeck M, Vogler P, Wagner RM, Zandanel F, Zanin R, Balmaverde B, Kataoka J, Rekola R, Takahashi Y
Publisher: EDP SCIENCES S A
: 2014
: Astronomy and Astrophysics
: ASTRONOMY & ASTROPHYSICS
: ASTRON ASTROPHYS
: A5
: 564
: 13
: 0004-6361
DOI: https://doi.org/10.1051/0004-6361/201322951
Results. Using customized Monte Carlo simulations corresponding to early MAGIC stereoscopic data, we detect NGC 1275 also in the earlier MAGIC campaign. The flux level and energy spectra are similar to the results of the second campaign. The monthly light curse above 100 GeV shows a hint of variability at the 3.6 sigma level. In the Fermi-LAT hand, both flux and spectral shape variabilities are reported. The optical light curve is also variable and shows a clear correlation with the gamma-ray flux above 100 MeV. In radio, three compact components are resolved in the innermost part of the jet. One of these components shows a similar trend as the Fermi-LAT and KVA light curves. The gamma-ray spectra measured simultaneously with MAGIC and Fermi-LAT from 100 MeV to 650 GeV can be well fitted either by a log-parabola or by a power-law with a subexponential cutoff for the two observation campaigns. A single-zone synchrotron-self-Compton model, with an electron spectrum following a power-law with an exponential cutoff, can explain the broadband spectral energy distribution and the multifrequency behavior of the source. However, this model suggests an untypical low bulk-Lorentz factor or a velocity alignment closer to the line of sight than the parsec-scale radio jet.
