Ar. Duncan et al., RADIO OBSERVATIONS OF THE X-RAY SUPERNOVA REMNANT G272.2-3.2, Monthly Notices of the Royal Astronomical Society, 289(1), 1997, pp. 97-104
Radio continuum observations are presented for the recently discovered
X-ray supernova remnant (SNR) G272.2 - 3.2. Radio emission from this
SNR has never before been detected, We find this remnant to have a non
-thermal radio spectral index of 0.55 +/- 0.15 (S proportional to lamb
da(alpha)), and an almost circular appearance with a diameter of appro
ximately 15 arcmin (in agreement with the X-ray size). High-resolution
observations with the Australia Telescope Compact Array (ATCA) reveal
the remnant to consist of a series of faint filaments and patches of
emission, with a maximum surface brightness of 10 mJy beam area(-1) at
1.4 GHz, and a diffuse emisson component, This diffuse emission appea
rs to be produced by shock-accelerated electrons, Modest spectral inde
x variations are seen across the SNR, indicating that G272.2 - 3.2 con
tains no significant thermal or plerionic component. Optical filaments
in the region appear to align well with the radio 'blobs', whilst the
X-ray enhancements show no correlation with the 'blobs', These correl
ations are consistent with a somewhat higher age for the remnant than
is derived from the X-ray data; perhaps 6 x 10(3) yr or so, Within the
sensitivity of the observations no polarized emission was detected fr
om G272.2 - 3.2, which is possibly indicative of a highly twisted magn
etic field.