Vol. 604
In section 6. Interstellar and circumstellar

The chemistry of episodic accretion in embedded objects. 2D radiation thermo-chemical models of the post-burst phase

by Ch. Rab, V. Elbakyan, E. Vorobyov, et al. A&A 604, A15


Using a new model for the chemistry of episodic accretion based on the 2D, radiation thermo-chemical disk code PRODIMO, the authors investigate observational signatures of the chemical evolution in the post-accretion burst phase for embedded protostellar sources. During an accretion burst, chemical species such as CO sublimate from the dust surfaces. When the burst ends, they freeze out again. This occurs from the inside out, because of the radial density gradient in the disk and envelope structure. The authors demonstrate that the inside-out freeze out produces clear observational signatures in spectral line emission, such as rings, and distinct features in the slope of radial intensity profiles. These can help identify post accretion burst targets in a model-independent way.