RT Journal Article T1 MAGIC observations of PG 1553+113 during a multiwavelength campaign in July 2006 A1 Antoranz Canales, Pedro A1 Barrio Uña, Juan Abel A1 Contreras González, José Luis A1 Fonseca González, María Victoria A1 López Moya, Marcos A1 Miranda Pantoja, José Miguel A1 Nieto Castaño, Daniel AB The active galactic nucleus PG1553+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 sigma. The integral flux above 150 GeV was (2.6 +/- 0.9) x 10(-7) ph s(-1) m(-2). By fitting the differential energy spectrum with a power law, a spectral index of -4.1 +/- 0.3 was obtained. PB EDP Sciencies SN 0004-6361 YR 2009 FD 2009-01 LK https://hdl.handle.net/20.500.14352/44001 UL https://hdl.handle.net/20.500.14352/44001 LA eng NO © ESO 2009. We would like to thank the IAC for the excellent working conditions at the Observatorio del Roque de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN and the Spanish CICYT is gratefully acknowledged. This work was also supported by ETH research grant TH-34/04-3 and by Polish grant MNiI 1P03D01028. NO German BMBF NO German MPG NO Italian INFN NO Spanish CICYT NO ETH NO Polish grant DS Docta Complutense RD 19 abr 2025