2015MNRAS.449.2259L

It has been pointed out that the masses of protostellar/protoplanetary discs may be underestimated systematically. In order to investigate the extent of the underestimation and to provide a hint for future observations, we calculate the masses of discs which form from the collapse of molecular cloud cores theoretically rather than artificially set the initial conditions of the discs. The distributions of parameters of molecular cloud cores are taken from observations. We give the disc mass distributions in the Class I and Class II phases of stellar evolution. We show that the disc masses around Class I objects ranges from 0.007 to 0.71M_☉ and the median value is 0.22M_☉, while the range of disc masses around Class II objects is from 10^–4 to 1.78M_☉ and the median value is 0.22M_☉ if the stellar mass distribution is the same as that of the host stars of the observed extrasolar planets. When we adopt the initial mass function of the stellar masses, the median values are 0.05 and 0.01M_☉ for disc masses around Class I and Class II objects, respectively. The mass distributions of discs around stars with masses less than 1M_☉ show smaller maximum values and median values. We conclude that the observed mass distributions are in the range of our results. The calculated maximum and mean values are however larger than those observed if the mass distribution is taken from the host stars of the observed extrasolar planets, while those values are nearly consistent with the observations if the initial mass function of the stellar masses is involved.