Abstract:
We analyze the mass distribution of cores formed in an isothermal, magnetized, turbulent, and self-gravitating
nearly critical molecular cloud model. Cores are identified at two density threshold levels. Our main results are
that the presence of self-gravity modifies the slopes of the core mass function (CMF) at the high-mass end. At
low thresholds, the slope is shallower than the one predicted by pure turbulent fragmentation. The shallowness
of the slope is due to the effects of core coalescence and gas accretion. Most importantly, the slope of the CMF
at the high-mass end steepens when cores are selected at higher density thresholds, or alternatively, if the CMF
is fitted with a lognormal function, the width of the lognormal distribution decreases with increasing threshold.
This is due to the fact that gravity plays a more important role in denser structures selected at higher density
threshold and leads to the conclusion that the role of gravity is essential in generating a CMF that bears more
resemblance to the IMF when cores are selected with an increasing density threshold in the observations.
