Detection of Very-High Energy Gamma-Rays from the BL Lac Object PG 1553+113 with the MAGIC Telescope

Wagner, Robert; Dorner, Daniela; Hayashida, Masaaki; et al.
Bibliographical reference

Proceedings of the 30th International Cosmic Ray Conference. July 3 - 11, 2007, Mérida, Yucatán, Mexico. Edited by Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia. Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008. Volume 3, p.889-892

Advertised on:
0
2008
Number of authors
4
IAC number of authors
0
Citations
2
Refereed citations
1
Description
The MAGIC telescope has observed very high energy gamma-ray emission from the BL Lac object PG 1553+113 in 2005 and 2006 at an overall significance is 8.8 sigma in 18.8h. The light curve shows no significant flux variations on a daily time-scale. The flux level during 2005 was, however, significantly higher compared to 2006. The differential energy spectrum between ~90 GeV and 500 GeV is well described by a power law with a spectral index of -4.2+-0.3. The inferred photon energy spectrum allows to pose an upper limit on the (yet undetermined) redshift of the PG 1553+113.