Polarimetric image of 3C 279 at 22GHz

Images in both total intensity and fractional polarization are reconstructed using RML method implemented in the eht-imaging library. The electric vector position angles are found to be mostly aligned with the general jet direction, suggesting a predominantly toroidal magnetic field, in agreement with the presence of a helical magnetic field.

Ground-space fringes were detected up to a projected baseline length of ~8G{lambda}, achieving the angular resolution of around 26uas. The fine-scale structure of the relativistic jet is found in our study extending to a projected distance of ~180 parsec from the radio core. However, the filamentary structure reported by previous RadioAstron observations of 2014 is not detected in our current study.