Contribution Contributed Talk
Complex Organic Nests of Low-Mass Protostars
Complex organic molecules are fused with low-mass star-forming systems. Such species have been observed on- and off-source in hot and cold environments, respectively [e.g., 1, 4, 5]. During the formation of the star-disk system these compounds can potentially contaminate protoplanetary and proto-cometary materials with organics. In this talk, physicochemical models are presented, including wavelength-dependent radiative transfer and an extensive gas-grain chemical network. Model results on the effects of dynamic infall from the prestellar core towards the protoplanetary disk will be discussed. A dedicated set of model results will be shown for the midplanes of disks and the ice content therein, which is expected to trace the dominant portion of the volatile material for the larger forming solid bodies. The results of our dynamical model are contrasted by the outcomes of a static model . Also, the distribution of complex organics themselves, i.e., trace species of the icy mantles, will be shown. Finally, the off-source distribution of complex organics is investigated by means of a static model on much larger scales of several thousand AU. The results show that the cavity walls illuminate in a time-dependent and species-variant fashion. In addition, a complex organic ice-rich torus in the inner envelope encompassing the young low-mass protostar appears in the simulations, which is not reflected in the gas phase. Furthermore, complex organics are demonstrated to have unique lifetimes and be grouped into early (formaldehyde, ketene, methanol, formic acid, methyl formate, acetic acid, glycolaldehyde) and late (acetaldehyde, dimethyl ether, ethanol) species .
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