Results of directly fitting the LOFAR visibilities. a: amplitudes of visibilities in the uv plane for the LOFAR observation. The background colour map shows a Gaussian fit. The red ellipse shows the FWHM of the normalised amplitude. b: visibility phase in the uv plane. The background colour map shows the fitted phase angle. c: visibility amplitudes received from different angular scales. The red curves indicate the FWHM of the semi-major and semi-minor axes of the fitted Gaussian.