Positional Correlation between Low-latitude Gamma-ray Sources and Snrs

We present the results of a spatial correlation analysis between unidentified gamma-ray sources in the 3EG catalog and candidates to supernova remnants. This work extends a previous study made by Romero, Benaglia & Torres (1999). We also consider the gamma-ray emission variability and the spectral index for the sources with positional coincidence. 1. SNRS AS GAMMA-RAY EMITTERS Supernova remnants (SNRs) are usually considered as the main sources of cosmic rays with energies below ∼ 1015 eV. Both electrons and protons are believed to be accelerated by Fermi mechanism in the expanding shock front of these objects. The electrons produce synchrotron emission detected at radio wavelengths whereas the interactions between relativistic protons and ambient nuclei can produce neutral pions, which quickly decay yielding γ-ray emission at energies E ≥ 100MeV, in the EGRET range. The expected γ-ray flux at Earth was given by Drury et al. (1994), F (≥ 100MeV) ∼ 4.4×10−7θ ESN 1051erg (