Image Details
Caption: Fig. 1.
Hard color vs. soft color normalized to the Crab Nebula, as explained in § 1. Each circle represents the average soft/hard color of one of the observations used for this paper. The triangles mark averages of 1 to 32 observations and are labeled with letters, in alphabetical order from (A) the island state, through (J) the lower left banana, to (N) the lower banana.
© 2008. The American Astronomical Society. All rights reserved. Printed in U.S.A.