Explanation of columns in output listings:

Flux is defined as the total of all of the image values included within the selected
  region times the area of an individual pixel. Only whole pixels are included. A pixel is
  included if any part of it is included in the selected region.

Area is the total number of pixels used times the area of each pixel.

Centroid and Standard Deviation are the mean and standard deviation of the moments
of the distribution (see map_xymoments.pro).

Peak location and value are computed by doing parabolic fits to the 9 pixels surrounding
  the image peak (see parapeak.pro).
  When the peak pixel is near the edge of the image, the peak location can not be determined
  (a "?" will be displayed in the list), and the peak value shown is just the highest image value.