Magic upper limits for two Milagro-detected bright fermi sources in the region of SNR G65.1+0.6

Abstract

We report on the observation of the region around supernova remnant G65.1+0.6 with the stand-alone MAGIC-I telescope. This region hosts the two bright GeV gamma-ray sources 1FGL J1954.3+2836 and 1FGL J1958.6+2845. They are identified as GeV pulsars and both have a possible counterpart detected at about 35 TeV by the Milagro observatory. MAGIC collected 25.5 hr of good quality data and found no significant emission in the range around 1 TeV. We therefore report differential flux upper limits, assuming the emission to be point-like (≤0.° 1) or within a radius of 0.° 3. In the point-like scenario, the flux limits around 1 TeV are at the level of 3% and 2% of the Crab Nebula flux for the two sources, respectively. This implies that theMilagro emission is either extended over a much larger area than our point-spread function or it must be peaked at energies beyond 1 TeV, resulting in a photon index harder than 2.2 in the TeV band. © 2010. The American Astronomical Society. All rights reserved.