Table 6: Beam-averaged results.

Model		 Beam-averaged column densities Face-on mass density Relative mass Ratio $N(~{\rm H_{2}})/I({\rm CO})$
  N(CO) N(C) $N(~{\rm H_{2}})$ $\sigma(~{\rm H_{2}})$ $\sigma_{\rm gas}^{a}$ components 1:2 X
  ( $10^{18} ~{\rm cm^{-2}}$) ( $10^{21} ~{\rm cm^{-2}}$) ($M_{\odot}$/pc-2)   (1020 mol $~{\rm cm^{-2}}/~{\rm {K~km ~s^{-1}}}$)

M 51; $N_{\rm H}/N_{\rm C}^{b}$ = 1250; N(HI) $^{c} = 2\times 10^{20} ~{\rm cm^{-2}}$

1		 0.36 4.4 2.9 43 60 0.6 : 0.4 0.74
2 0.36 1.2 1.0 15 20 0.4 : 0.6 0.25
3 0.42 3.3 2.2 33 47 0.8 : 0.2 0.41
Note: a Sum of $~{\rm H_{2}}$ and HI multiplied by 1.35 to take into account the contribution by helium;
b See text, Sect. 4.2; c HI column density valid for both Center and (nearby) Arm; Tilanus & Allen (1991).

Source LaTeX | All tables | In the text