We present total-intensity and polarized-intensity images of the Cygnus Loop supernova remnant(SNR)observed by the Five-hundred-meter Aperture Spherical radio Telescope.The high angular-resolution and high-sensitivity images enable us to thoroughly compare the properties of the northern part with the southern part of the SNR.The central filament in the northern part and the southern part have a similar foreground rotation measure,meaning their distances are likely similar.The polarization analysis indicates that the random magnetic field is larger than the regular field in the northern part,but negligible in the southern part.The total-intensity image is decomposed into components of various angular scales,and the brightness-temperature spectral index of the shell structures in the northern part is similar to that in the southern part in the component images.All the evidence suggests that the northern and southern parts of the Cygnus Loop are situated and thus evolved in different environments of interstellar medium,while belonging to the same SNR.

School of Physics and Astronomy,Yunnan University,Kunming 650500,China;National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;CAS Key Laboratory of FAST,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;Max-Planck-Institut für Radioastronomie,Auf dem Hügel,53121 Bonn,Germany;Institut für Physik und Astronomie,Universit?t Potsdam,Haus 28,Karl-Liebknecht-Str.24/25,D-14476 Potsdam,Germany;Deutsches Elektronen-Synchrotron DESY,Platanenallee 6,D-15738 Zeuthen,Germany

[1]Xiao-Hui Sun;Xu-Yang Gao;Wolfgang Reich;Peng Jiang;Di Li;Huirong Yan;Xiang-Hua Li-.New Continuum and Polarization Observations of the Cygnus Loop with FAST.Ⅱ.Images and Analyses)[J].天文和天体物理学研究,2022(12):249-259

Cygnus

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