Extragalactic H2 and its variable relation to CO
Abstract
Description
A steep metallicity dependence of the CO-to-H2 conversion factor X of the form log X = 12.2 - 2.5 log[O]/[H], based on a sample of 20 (extra)galactic determinations, is presented and discussed. The apparently less steep dependence found from millimeter interferometer observations is explained within the context of photon-dominated regions.
4 pages, 2 figures, in: "H2 in Space", Cambridge University Press, ed. F. Combes and G. Pineau des Forets
4 pages, 2 figures, in: "H2 in Space", Cambridge University Press, ed. F. Combes and G. Pineau des Forets