2000A&A...358..494B

A sensitive search for CO emission from the Low Surface Brightness Galaxy Malin 1 has yielded negative results. The nucleus and several positions corresponding to regions of star formation in the disk were observed in the CO(1-0) and CO(2-1) lines with no detection. Use of a ``standard'' N(H₂)/I_CO(1–0) conversion factor yields M_H2/M_HI<0.03. However, rather than argue that there is very little molecular gas in Malin 1, where some star formation is currently taking place, we attribute the non-detection chiefly to the low temperature of the gas. Detection of CO may be rendered still more difficult by a subsolar metallicity.