by $$M_{\textrm{vir}} \,[M_\odot] = 190 \sigma_{v}^2\,[{\rm kms}^{-1}]\, r\, [{\rm pc}]
  \label{eq:virial_mass2}$$ according to MacLaren et al. (1988). The results of our analysis for each cloud are given in Table 1.

From Table \[tab:clouds\_properties\] we see that the virial masses are a factor 3-6 larger than the masses derived from the integrated CO emission for the resolved molecular clouds in 30 Doradus. Therefore, the conversion factor between the H$_2$ column density and the CO intensity is, on average, 4.5 times the Galactic value. This translates into a conversion factor $X_{\textrm{CO}} = 1.0 \pm 0.4 \times 10^{21}$ cm$^{-2}$ (K km s$^{-1}$)$^{-1}$. [@israel97] estimated the H$_2$ column densities towards CO clouds in the LMC and SMC from far-infrared surface brightness, and derived, in units of $10^{21}$ cm$^{-2}$ (K km s$^{-1}$)$^{-1}$, $X_{\textrm{CO}} = 12 \pm 2$ and $X_{\textrm{CO}} = 1.3 \pm 0.2$ for the SMC and LMC, respectively. [@israel03] found, in units of $10^{20}$ cm$^{-2}$ (K km s$^{-1}$)$^{-1}$, $X_{\textrm{CO}} = 4.8 \pm 1.0$ and $X_{\textrm{CO}} =
4.3 \pm 0.6$ for the SMC and LMC, respectively. [@garay02] derived $X_{\textrm{CO}} = 6.4 \times 10^{20}$ cm$^{-2}$ (K km s$^{-1}$)$^{-1}$ for the Complex-37 in the LMC. [@johansson98] also derived conversion factors close to the canonical value for the 