Published online by Cambridge University Press: 25 November 2011
We report a study of the relation between dust and gas over a 100 deg2 area inthe Taurus molecular cloud. We compare the H2 column density derived from dustextinction with the CO column density derived from the 12CO and 13COJ = 1 → 0 lines. We derive the visual extinction from reddeningdetermined from 2MASS data. The comparison is done at an angular size of 200′′,corresponding to 0.14 pc at a distance of 140 pc. We find that the relation between visualextinction AV and N(CO) is linear betweenAV ≃ 3 and 10 mag in the region associated with theB213–L1495 filament. In other regions the linear relation flattens forAV ≳ 4 mag. Accounting for the observed relation between thecolumn density of CO and CO2 ices and AV, we find alinear relationship between the column of carbon monoxide and dust for observed visualextinctions up to the maximum value in our data ≃23 mag.