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

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 (2.6 ± 0.9) × 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. © ESO 2009.