Research Note

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

¹ 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 5.0σ. The integral flux above 150 GeV was . By fitting the differential energy spectrum with a power law, a spectral index of was obtained.