Peering into the Milky Way by FAST:Ⅳ. Identification of two new Galactic supernova remnants G203.1+6.6and G206.7+5.9

作者：XuYang Gao^*; Wolfgang Reich; XiaoHui Sun^*; He Zhao; Tao Hong; ZhongSheng Yuan; Patricia Reich; JinLin Han^*

来源：Science China Physics,Mechanics & Astronomy, 2022, 65(12): 59-71.

A 5°× 7°sky area containing two large radio structures of G203.1+6.6 and G206.7+5.9 with a size of about 2.°5 and 3.°5 respectively is scanned by using the L-band 19-beam receiver of the Five-hundred-meter Aperture Spherical radio Telescope(FAST).The FAST L-band receiver covers a frequency range of 1.0-1.5 GHz. Commissioning of the receiving system, including the measurements of the half-power beam width, gain, and main-beam efficiency is made by observing the calibrators. The multi-channel spectroscopy backend mounted to the receiver allows an in-band spectral-index determination. The brightness-temperature spectral indices of both objects are measured to be β ～ –2.6 to –2.7. Polarized emission is detected from the archival Effelsbergλ11 cm data for all the shell structures of G203.1+6.6 and G206.7+5.9. These results clearly indicate a non-thermal synchrotron emitting nature, confirming that G203.1+6.6 and G206.7+5.9 are large shell-type supernova remnants(SNRs). Based on morphological correlation between the radio continuum emission of G206.7+5.9 and the H i structures, the kinematic distance to this new SNR is estimated to be about 440 pc, placing it in the Local Arm.

• 单位
  云南大学; 中国科学院大学