Image Details
Caption: Fig. 11.
X‐ray colors C21 and C32 are plotted against one another for the group 1 galaxies. These galaxies have been subdivided into three ﹩L^{h}_{\mathrm{X}\,}/L_{B}﹩ classes; the symbols and corresponding luminosity ratio ranges are shown at the upper left. We have also plotted the colors of the two spiral bulges NGC 1291 (left) and M31 (right) as filled hexagons. The faintest X‐ray galaxies have colors consistent with those of the two bulges (hexagons), but the five brightest group 1 galaxies (open squares) have distinctly different colors. These five galaxies are NGC 5866, NGC 4382, NGC 4697, NGC 4365, and NGC 1380.
© 1998. The American Astronomical Society. All rights reserved. Printed in U.S.A.