②Steer-type Algorithm
The steer-type restoration algorithm,
called here, is the modified CLEAN algorithm proposed by Steer et
al. (1984, A&A, 137, 159). The
Steer-type algorithm deals radio sources in a group rather than individually. Components
brighter than a certain fraction of the peak brightness of
the dirty image are regarded as a group, which are called a contour-trim. The fraction of contour-trim has to be higher than the normalized level of the secondlobes. The dirty contour-trim is created by the contour-trim and the dirty beam, then, is extracted with the CLEAN loop
gain.