Chemical Evolution Modeling: Comparing Empirical & Static Models

[wolram]

http://arxiv.org/abs/astro-ph/0506086

Authors: Jeong-Eun Lee, Neal J. Evans II, Edwin A. Bergin
Comments: 13 pages, 12 figures, To be published in the Astrophysical Journal

We compare an evolutionary chemical model with simple empirical models of the abundance and with static chemical models. We focus on the prediction of molecular line profiles that are commonly observed in low mass star forming cores. We show that empirical models can be used to constrain evaporation radii and infall radii using lines of some species. Species with more complex abundance profiles are not well represented by the empirical models. Static chemical models produce abundance profiles different from those obtained from an evolutionary calculation because static models do not account for the flow of matter inward from the outer regions. The resulting profiles of lines used to probe infall may differ substantially.

 

[lippyka]

In the case of species with a large dynamic range, the infall profile is quite distinct even for very small abundances of the species. We find that the evolution of the abundance can be significant and should be taken into account when interpreting observations.