Image Details
Caption: Fig. 1.
ALPHA plots of the Crab Nebula (left) and 1ES 1959+650 (right) after cuts on image parameters. Both diagrams show the second‐order curve used for estimating the background at low ALPHA (up to 9°). In the left diagram (Crab Nebula), we have also added the (normalized) off‐source data.
© 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A.