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

Abstract

A new faint and large shell-type radio Supernova Remnant (SNR) G108.2−0.6 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( S ν∝ν α ), typical of a shell-type SNR. The remnant’s flux density at 1420 MHz is 6.6 ± 0. 7J y, 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 (Σ1 GHz = 2.4 × 10 −22 Wm −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 G108.2−0.6.