ON THE NATURE OF THE STRONG EMISSION-LINE GALAXIES IN CLUSTER CL-0024- ARE SOME THE PROGENITORS OF LOW-MASS SPHEROIDALS(1654 )

We present new size, line ratio; and velocity width measurements for s ix strong emission-line galaxies in the galaxy cluster, Cl 0024+1654, at redshift z similar to 0.4. The velocity widths from Keck spectra ar e all narrow (30 less than or similar to sigma less than or similar to 120 km s(-1)), with three profiles showing double peaks. Four galaxie s have low masses (M less than or similar to 10(10) M.). Whereas three galaxies were previously reported to be possible active galactic nucl ei (AGNs), none exhibit AGN-like emission-line ratios or velocity widt hs. Two or three appear as very blue spirals with the remainder more a kin to luminous H II galaxies undergoing a strong burst of star format ion. We propose that after the burst subsides, these galaxies will tra nsform into quiescent dwarfs, and that they are thus progenitors of so me cluster spheroidals(3) seen today.