Cooling flow star formation and the apparent stellar ages of elliptical galaxies

Simple theoretical arguments indicate that cooled interstellar gas in brigh t elliptical galaxies forms into a young stellar population having a bottom -heavy but optically luminous initial mass function extending to similar to 2 M.. When the colors and spectral features of this young population are c ombined with those of the underlying old stellar population, the apparent a ges are significantly reduced, similar to the relatively young apparent age s observed in many elliptical galaxies. Galactic mergers are not required t o resupply young stars. The sensitivity of continuous star formation to L-B and L-X/L-B is likely to account for the observed spread in apparent ages among elliptical galaxies. Local star formation is accompanied by enhanced stellar H beta equivalent widths, stronger optical emission lines, more the rmal X-ray emission, and lower apparent temperatures in the hot gas. The yo ung stars should cause M/L to vary with galactic radius, perturbing the fun damental plane of the old stars alone.