A&A 493, 467-469 (2009)
DOI: 10.1051/0004-6361:20079048

Research Note

MAGIC observations of PG 1553+113 during a multiwavelength campaign in July 2006

J. Albert¹, E. Aliu², H. Anderhub³, P. Antoranz⁴, C. Baixeras⁵, J. A. Barrio⁴, H. Bartko⁶, D. Bastieri⁷, J. K. Becker⁸, W. Bednarek⁹, A. Berdyugin¹⁰, K. Berger¹, C. Bigongiari⁷, A. Biland³, R. K. Bock⁶, P. Bordas⁵, V. Bosch-Ramon⁵, T. Bretz¹, I. Britvitch³, M. Camara⁴, E. Carmona⁶, A. Chilingarian¹¹, S. Commichau³, J. L. Contreras⁴, J. Cortina², M. T. Costado^{12, 13}, V. Curtef⁸, V. Danielyan¹¹, F. Dazzi⁷, A. De Angelis¹⁴, C. Delgado¹², R. de los Reyes⁴, B. De Lotto¹⁴, D. Dorner¹, M. Doro⁷, M. Errando², M. Fagiolini¹⁵, D. Ferenc¹⁶, E. Fernández², R. Firpo², M. V. Fonseca⁴, L. Font⁵, M. Fuchs⁶, N. Galante⁶, R. J. García-López^{12, 13}, M. Garczarczyk⁶, M. Gaug¹², F. Goebel⁶, D. Hakobyan¹¹, M. Hayashida⁶, T. Hengstebeck¹⁷, A. Herrero^{12, 13}, D. Höhne¹, J. Hose⁶, C. C. Hsu⁶, S. Huber¹, P. Jacon⁹, T. Jogler⁶, R. Kosyra⁶, D. Kranich³, R. Kritzer¹, A. Laille¹⁶, E. Lindfors¹⁰, S. Lombardi⁷, F. Longo¹⁸, M. López⁴, E. Lorenz^{3, 0, 6}, P. Majumdar⁶, G. Maneva¹⁹, K. Mannheim¹, M. Mariotti⁷, M. Martínez², D. Mazin², C. Merck⁶, M. Meucci¹⁵, M. Meyer¹, J. M. Miranda⁴, R. Mirzoyan⁶, S. Mizobuchi⁶, A. Moralejo⁶, D. Nieto⁴, K. Nilsson¹⁰, J. Ninkovic⁶, E. Oña-Wilhelmi², N. Otte⁶, I. Oya⁴, M. Panniello¹², R. Paoletti¹⁵, M. Pasanen¹⁰, D. Pascoli⁷, F. Pauss³, R. Pegna¹⁵, M. Persic¹⁸, L. Peruzzo⁷, A. Piccioli¹⁵, E. Prandini⁷, N. Puchades², A. Raymers¹¹, J. Rico², W. Rhode⁸, J. Rico², M. Rissi³, A. Robert⁵, S. Rügamer¹, A. Saggion⁷, T. Y. Saito⁶, A. Sánchez⁵, P. Sartori⁷, V. Scalzotto⁷, V. Scapin¹⁴, R. Schmitt¹, T. Schweizer¹⁷, M. Shayduk¹⁷, K. Shinozaki⁶, S. N. Shore²⁰, N. Sidro², A. Sillanpää¹⁰, D. Sobczynska⁹, F. Spanier¹, A. Stamerra¹⁵, L. S. Stark³, L. Takalo¹⁰, P. Temnikov¹⁹, D. Tescaro², M. Teshima⁶, D. F. Torres^{2, 21}, N. Turini¹⁵, H. Vankov¹⁹, A. Venturini⁷, V. Vitale¹⁴, R. M. Wagner⁶, T. Wibig⁹, W. Wittek⁶, F. Zandanel⁷, R. Zanin², and J. Zapatero<sup>5

1</sup>  Universität Würzburg, 97074 Würzburg, Germany
    e-mail: daniela.dorner@unige.ch
²  IFAEnergies, Edifici Cn., 08193 Bellaterra, Spain
³  ETH Zürich, 8093 Hönggerberg, Switzerland
⁴  Universidad Complutense, 28040 Madrid, Spain
⁵  Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
⁶  Max-Planck-Institut für Physik, 80805 München, Germany
⁷  Università di Padova and INFN, 35131 Padova, Italy
⁸  Universität Dortmund, 44227 Dortmund, Germany
⁹  University of Łódź, 90236 Lodz, Poland
¹⁰  Tuorla Observatory, 21500 Piikkiö, Finland
¹¹  Yerevan Physics Institute, 375036 Yerevan, Armenia
¹²  Inst. de Astrofisica de Canarias, 38200, La Laguna, Tenerife, Spain
¹³  Depto. de Astrofisica, Universidad, 38206 La Laguna, Tenerife, Spain
¹⁴  Università di Udine, and INFN Trieste, 33100 Udine, Italy
¹⁵  Università di Siena, and INFN Pisa, 53100 Siena, Italy
¹⁶  University of California, Davis, 95616-8677, USA
¹⁷  Humboldt-Universität zu Berlin, 12489 Berlin, Germany
¹⁸  Università di Trieste, and INFN Trieste, 34100 Trieste, Italy
¹⁹  Institute for Nuclear Research and Nuclear Energy, 1784 Sofia, Bulgaria
²⁰  Università di Pisa, and INFN Pisa, 56126 Pisa, Italy
²¹  Institut de Ciències de l'Espai, 08193 Bellaterra, Spain

Received 12 November 2007 / Accepted 10 October 2008

Abstract
The active galactic nucleus PG 1553+113 was observed by the MAGIC telescope in July 2006 during a multiwavelength campaign, in which telescopes in the optical, X-ray, and very high energies participated. Although the MAGIC data were affected by strong atmospheric absorption (calima), they were analyzed after applying a correction. In 8.5 h, a signal was detected with a significance of 5.0. The integral flux above 150 GeV was . By fitting the differential energy spectrum with a power law, a spectral index of was obtained.

Key words: gamma rays: observations -- galaxies: active -- galaxies: BL Lacertae objects: individual: PG 1553+113

© ESO 2009

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