We report here the results of a search for radio counterparts in the environs of three 3EG sources located in Capricornus region, namely 3EG J1834-2803, 3EG J1847-3219, and 3EG J1850-2652, using preexisting 408-MHz continuum data and new 2.326-GHz continuum and neutral hydrogen line observations.
We have eliminated the contaminating diffuse emission from the radio continuum images with a well-proven filtering technique, and found that an extended non-thermal radio feature, centered at (l,b) » (+6.5°,-12.0°), is the most remarkable object in the field. The source is a low-brightness, shell-type structure, which very much resembles a typical SNR. It presents a limb brightened shell of size ~ 8° ×8°, with an integrated flux at 408 MHz of ~ 130 ±20 Jy. Clear evidence for HI clouds was found at the best position of 3EG J1834-2803 and 3EG J1850-2652 from -2 Km s-1 up to +4 Km s-1. The high value of b ( ~ 12°) and the HI data circunscribe the distance to d < 470 pc, if the source is located within the galactic disk.
We suggest that the radio source could be the result of a SN whose remnant is expanding through a cloudy ISM. When the front shock interacts with an interstellar cloud, locally accelerated cosmic rays are convected into it producing a region of strong g-ray emission through hadronic collisions and subsequent neutral pion decays. This scenario provides a faithful representation of the main observed features. We have estimated several physical parameters within this context.