NED object is NGC 6251; Reference is 1977MNRAS.181..465W Figure 1. (a) 151-MHz total intensity 1. Beam size 3.7 X 3.7 arcmin FWHM. The contour interval is 70 mJy per (beam area), ~ 2{sigma}. Zero and negative contours are omitted. Peak values are given in units of the contour interval.