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-h...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 beβ~-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.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2021YFA1600401,and 2021YFA1600400)the National Natural Science Foundation of China(Grant No.11988101)+4 种基金and the National SKA Program of China(Grant No.2022SKA0120103)the CAS-NWO Cooperation Program(Grant No.GJHZ1865)the Open Project Program of the Key Laboratory of FAST,NAOC,Chinese Academy of Sciencessupported by the Cultivation Project for FAST Scientific Payoff and Research Achievement of CAMS-CAS,and the Science&Technologysupported by the National Natural Science Foundation of China(Grant No.12003044)。
文摘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 beβ~-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.
