%0 Journal Article
%A Antoranz Canales, Pedro
%A Barrio Uña, Juan Abel
%A Contreras González, José Luis
%A Fonseca González, María Victoria
%A Miranda Pantoja, José Miguel
%A Scapin, Valeria
%T PG 1553+113: Five years of observations with MAGIC
%D 2012
%@ 0004-637X
%U https://hdl.handle.net/20.500.14352/43807
%X We present the results of five years (2005-2009) of MAGIC observations of the BL Lac object PG 1553+113 at very high energies (VHEs; E > 100 GeV). Power-law fits of the individual years are compatible with a steady mean photon index Gamma = 4.27 +/- 0.14. In the last three years of data, the flux level above 150 GeV shows a clear variability (probability of constant flux < 0.001%). The flux variations are modest, lying in the range from 4% to 11% of the Crab Nebula flux. Simultaneous optical data also show only modest variability that seems to be correlated with VHE gamma-ray variability. We also performed a temporal analysis of (all available) simultaneous Fermi/Large Area Telescope data of PG 1553+113 above 1 GeV, which reveals hints of variability in the 2008-2009 sample. Finally, we present a combination of the mean spectrum measured at VHEs with archival data available for other wavelengths. The mean spectral energy distribution can be modeled with a one-zone synchrotron self-Compton model, which gives the main physical parameters governing the VHE emission in the blazar jet.
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