HDF Scattered Light Subtraction:

The HDF observations were carefully scheduled to minimize the effect of scattered light. Nevertheless, Scattered light from the bright earth produces a visible X pattern in about 25% of the HDF data frames. The attached figure shows the distribution of mean sky backgrounds actually obtained. The filled-in portion of the histograms indicates data where the scatttered light patern is visible to the eye. In most cases the higher background associated with the scattered light has only a very small effect on the resultant S/N for faint objects. However, the X pattern is not terribly pleasing to the eye, and may cause problems for some object detection algorithms.

A major difference between version 1 and version 2 of the data reduction was the treatment of scattered light. Details can be found below:

Copyright © 1997 The Association of Universities for Research in Astronomy, Inc. All Rights Reserved.

Harry Ferguson ferguson@stsci.edu 3/1/96