Connecting the Dots: Analyzing Synthetic Observations of Star-Forming Clumps in Molecular Clouds
Abstract
In this paper, we investigate the extent to which observations of molecular
clouds can correctly identify and measure star-forming clumps. We produced a
synthetic column density map and a synthetic spectral-line data cube from the
simulated collapse of a 5000 M$_{\odot}$ molecular cloud. By correlating the
clumps found in the simulation to those found in the synthetic observations,
clump masses derived from spectral-line data cubes were found to be quite close
to the true physical properties of the clumps. We also find that the `observed'
clump mass function derived from the column density map is shifted by a factor
of ~ 3 higher than the true clump mass function, due to projection of
low-density material along the line of sight. Alves et al. (2007) first
proposed that a shift of a clump mass function to higher masses by a factor of
3 can be attributed to a star formation efficiency of 30 %. Our results
indicate that this finding may instead be due to an overestimate of clump
masses determined from column density observations.