CONTINUUM EMISSION BY COOLING CLOUDS

The collapse of baryons into the center of a host dark matter halo is accompanied by radiation that may be detectable as compact (less than or similar to 10 kpc) UV-continuum and Ly alpha emission with Ly alpha luminosities as high as similar to 10(42)-10(43) erg s(-1) in halos of mass M = 10(11)-10(12) M(circle dot). We show that the observed equivalent width (EW) of the Ly alpha line emitted by these cooling clouds is EW less than or similar to 400 angstrom ( rest frame). These luminosities and EWs are comparable to those detected in narrowband surveys for redshifted Ly alpha emission. The rest-frame ultraviolet of Ly alpha-emitting cooling clouds radiation may be dominated by two-photon transitions from 2s -> 1s. The resulting spectrum can distinguish cooling clouds from a broad class of young star-forming galaxies.