SIMBAD references

The rich cluster of galaxies Cl 0024+1654 (z = 0.39) was observed with the Infrared Space Observatory. Forty seven sources were detected at 14.3 µm, and 19 of them are associated with spectroscopically confirmed cluster galaxies. The spectral energy distributions and star formation rates derived from the mid-infrared luminosities have revealed that the cluster sources are luminous (L_IR∼6.5x10¹⁰-4x10¹¹L_☉) star-forming (∼11-69 M_☉/yr) galaxies. The optical star formation rates are at least an order of magnitude lower, implying that most of the star forming activity is hidden by dust. Cl 0024+1654 is in the process of colliding with a smaller cluster located along the line of sight and presents a strong optical Butcher-Oemler effect. The population of active star-forming galaxies with a widespread distribution in the cluster and presenting disturbed morphologies is believed to be a consequence of the collision.