A search for TeV gamma-ray emission from SNRs, pulsars and unidentified GeV sources in the Galactic plane in the longitude range between -2° and 85°

Abstract

Using the HEGRA system of imaging atmospheric Cherenkov telescopes, one quarter of the Galactic plane (-2° < l < 85°) was surveyed for TeV gamma-ray emission from point sources and moderately extended sources (∅ ≤ 0.8°). The region covered includes 86 known pulsars (PSR), 63 known supernova remnants (SNR) and nine GeV sources, representing a significant fraction of the known populations. No evidence for emission of TeV gamma radiation was detected, and upper limits range from 0.15 Crab units up to several Crab units, depending on the observation time and zenith angles covered. The ensemble sums over selected SNR and pulsar subsamples and over the GeV-sources yield no indication of emission from these potential sources. The upper limit for the SNR population is 6.7% of the Crab flux and for the pulsar ensemble is 3.6% of the Crab flux.