Can We Trust the Dust? Evidence of Dust Segregation in Molecular Clouds

摘要: Maps of estimated dust column density in molecular clouds are usually assumed to reliably trace the total gas structure. In this work we present results showing a clear discrepancy between and distribution Taurus cloud complex. We compute power spectrum 2MASS extinction map region find that it is much shallower than 13CO same was previously analyzed. This could be explained as effect grain growth on efficiency. However, would require wide range maximum sizes, which ruled out based constraints from curve available models. show major effects due CO formation depletion also out. Our result may therefore suggest existence intrinsic spatial fluctuations dust-to-gas ratio, with amplitude increasing toward smaller scales. Preliminary numerical simulations trajectories inertial particles turbulent flows illustrate how process clustering grains by turbulence lead observable effects. these cannot directly applied large-scale supersonic magnetized at present.