Detection of a new, low-brightness supernova remnant possibly associated with EGRET sources

¹ Instituto Argentino de Radioastronomía, C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
² Department of Physics & Electronics, Rhodes University, Grahamstown 6140, South Africa

Received: 19 September 2000
Accepted: 17 November 2000

Abstract

We report on the discovery of a shell-type supernova remnant in the southern sky. It is a large (∼8), low-brightness source with a nonthermal radio spectrum, which requires background filtering to isolate it from the diffuse background emission of the Galaxy. Three 3EG γ-ray sources are spatially correlated with the radio structure. We have made 21-cm line observations of the region and found that two of these sources are coincident with HI clouds. We propose that the γ-ray emission is the result of hadronic interactions between high-energy protons locally accelerated at the remnant shock front and atomic nuclei in the ambient clouds.