1994A&A...284..403B

The starburst dwarf galaxy He 2-10 has been partially mapped in the H₂(1-0) S1 line, and in the ¹²CO 3->2, 2->1 and 1->0 transitions. The ¹³CO lines for these transitions have also been measured at the center position. The observations show that the H₂ line is most likely shock excited, while the CO measurements indicate the presence of both cold (T_ex < 10 K) and hot (T_ex > 50 K) molecular gas. The hot molecular gas must be optically thin in all three ¹²CO transitions, and have a [¹²CO]/[¹³CO] isotopic abundance ratio of about 30. The cold J=1-0 emission is either optically thin with a similar isotopic abundance ratio, or optically thick with an anomalously high [¹²CO]/[¹³CO] ratio >100. Estimates for the total molecular gas mass and the dust mass are derived and compared with those of NGC 1569 and IIZw40. The starburst process appears to proceed in a similar manner in all three galaxies.