The most galactic centre survey-II. new results on published supernova remnants and g2.4 + 1.4

Abstract

Within the boundaries of the recent Molonglo Observatory Synthesis Telescope (MOST) 843-MHz survey of the Galactic Centre, there are 10 objects currently believed to be supernova remnants. This paper discusses the new MOST results on these objects. All but one were found to have properties consistent with earlier work. The exception, G358.4-1.9, was instead found to have characteristics suggesting a thermal origin. Also discussed is G2.4+1.4, a shell-like object which has been reported to have a non-thermal radio spectrum. This is at odds with other indicators which favour a thermal, mass-loss bubble model. The reported spectrum is here shown to be in error, with the new data implying a spectral index of a =-0.13 (S.,cc va). This removes the last existing evidence for a non-thermal radio emission mechanism for this object.