Suzaku Observation of G359.79$-$0.26, a New Supernova Remnant Candidate in the Galactic Center

Abstract

Abstract Utilizing Suzaku observations, we obtained the X-ray spectrum of G359.79$-$0.26, an extended X-ray feature nearby the Galactic center (GC) supernova remnant (SNR) SgrA East. We estimated the contribution from the Galactic center diffuse X-rays, which allows us a proper background subtraction from the faint extended source. A thin thermal plasma with a temperature of $ kT_{\rm e} \sim 1$keV and slightly enhanced metal abundances (S and Ar) are required to reproduce the G359.79$-$0.26 spectrum. The absorption column density ($N_{\rm H} \sim 4 \times 10^{22}$ cm$^{-2}$) associated with the plasma indicates that G359.79$-$0.26 is located in the GC. The thermal energy of the plasma is estimated to be $1.7 \times 10^{50}$erg, typical for galactic SNRs. Its center-filling X-ray emission surrounded by a shell-like radio structure suggests that G359.79$-$0.26 would be a new member of the mixed-morphology SNR class. The 2.45keV mosaic image covering a $\sim 40' \times 40'$ GC field implies an alternative possibility that G359.79$-$0.26 might be a part of a large ring-like structure with a size of $18' \times 16'$.