A MODEL FOR THE CONTINUUM ENERGY-DISTRIBUTION OF THE ULTRALUMINOUS GALAXY IRAS-F10214+4724

If early-type galaxies use up most of their gas to form stars in times short compared to their collapse times, and if a roughly constant fra ction of metals is locked up in dust grains, these galaxies may easily become opaque to starlight and emit most of their luminosity in the f ar-infrared. The corresponding spectral energy distribution matches re markably well the observed continuum spectrum of the ultraluminous gal axy IRAS F 10214 + 4724 from ultraviolet to submillimetre wavelengths, i.e. over almost 4 decades in frequency, for a galactic age less than or similar to 1 Gyr. The bolometric luminosity in this model is congr uent-to 2.7 x 10(14) L. (H-0 = 50 km s-1 Mpc-1, OMEGA = 1), i.e. somew hat lower than that implied by previous models. In the present framewo rk, the bolometric luminosity of the galaxy is expected to decrease by a factor greater than or similar to 30 during the subsequent evolutio n.