gamma ray astronomy with muons

Although gamma ray showers are muon poor, they still produce a number of muons sufficient to make the sources observed by GeV and TeV telescopes observable also in muons. For sources with hard gamma ray spectra there is a relative ''enhancement'' of muons from gamma ray primaries as compared to that from nucleon primaries. All shower gamma rays above the photoproduction threshold contribute to the number of muons N-mu, which is thus proportional to the primary gamma ray energy. With gamma ray energy 50 times higher than the muon energy and a probability of muon production by the gamma's of about 1%, muon detectors can match the detection efficiency of a GeV satellite detector if their effective area is larger by 10(4). The muons must have enough energy for sufficiently accurate reconstruction of their direction for doing astronomy. These conditions are satisfied by relatively shallow neutrino detectors such as AMANDA and Lake Baikal, and by y ray detectors such as MILAGRO. TeV muons from gamma ray primaries, on the other hand, are rare because they are only produced by higher energy y rays whose flux is suppressed by the decreasing flux at the source and by absorption on interstellar light. We show that there is a window of opportunity fbr muon astronomy with the AMANDA, Lake Baikal, and MILAGRO detectors.