Minimum value of pixon_sizes in pixels. Any structure at scales less than this pixon size are not allowed. Set to larger value to smooth out the final pixon map to avoid over-resolution.
For example, use 1 arcsec pixels and set pixon_resolution to 3.0 or 4.0 to smooth out the image to 3 or 4 arcsecs.
This is rather restrictive. A more subtle and possibly better way to avoid over-resolution is to use the pixon_sensitivity parameter.