Discovery of a new faint radio SNR G108.2-0.6

Abstract

A new faint and large shell-type radio Supernova Remnant (SNR) G 108.2-0.6 has been discovered in the Canadian Galactic Plane Survey (CGPS). The SNR shows an elliptical shell-type structure at 1420 MHz, and has a 408-1420 MHz TT-plot spectral index of α = -0.5 ±0.1 (Sν∝να) , typical of a shell-type SNR. The remnant's flux density at 1420 MHz is 6.6 ±0.7 Jy, and at 408 MHz is 11.5 ±1.2 Jy. Both of these are corrected for compact sources. An integrated spectral index of -0.45 ±0.13 is determined. This new SNR has among the lowest surface brightness of any known remnants (Σ1GHZ = 2.4 × 10-22 W m-2 Hz-1 sr-1). 21 cm Stokes Q and U CGPS data (plus preliminary Effelsberg Q and U maps) show some suggestive features that correlate with total power. H I observations show structures associated with G108.2-0.6 in the radial velocity range -53 to -58 km s-1, and indicate it is located in the Perseus arm shock at a distance of 3.2 ±0.6 kpc. At this distance the diameter of G108.2-0.6 is 58 pc. IRAS maps (12, 25, 60 and 100 μm) of the new SNR show rich infrared emission surrounding G 108.2-0.6. © ESO 2007.