A SEARCH FOR MILLIMETER-WAVE CO EMISSION IN DAMPED LYMAN-ALPHA SYSTEMS

A sensitive search for millimeterwave CO emission in 8 damped Lyman-al pha systems, 3 heavy element absorption line systems and one emission line galaxy, at redshifts ranging from 0.5 to 2.8, have yielded upper limits to the amount of molecular gas. The limits still allow relative ly high H-2 masses, but our results show that damped Lyman-alpha syste ms are not similar to the hyperluminous infrared galaxies at high reds hifts found in the IRAS database. One tentative detection of CO emissi on at z(a) = 2.47 remains, but is very uncertain. We are not able to c onfirm a claimed detection of CO emission at z(a) = 2.14 towards Q0528 -250.