Physicochemical models: source-tailored or generic?

TL;DR

This study compares source-tailored and generic physicochemical models to determine their effectiveness in explaining molecular abundances in young protostars, finding physical conditions have a greater impact than chemical details.

Contribution

It demonstrates that physical conditions dominate chemical outcomes, suggesting generic models are sufficient for understanding early star formation chemistry.

Findings

Physical conditions significantly influence molecular abundances.

Chemical model differences have minor impact compared to physical parameters.

Generic models facilitate comparative studies across star-forming regions.

Abstract

Physicochemical models can be powerful tools to trace the chemical evolution of a protostellar system and allow to constrain its physical conditions at formation. The aim of this work is to assess whether source-tailored modelling is needed to explain the observed molecular abundances around young, low-mass protostars or if, and to what extent, generic models can improve our understanding of the chemistry in the earliest stages of star formation. The physical conditions and the abundances of simple, most abundant molecules based on three models are compared. After establishing the discrepancies between the calculated chemical output, the calculations are redone with the same chemical model for all three sets of physical input parameters. With the differences arising from the chemical models eliminated, the output is compared based on the influence of the physical model. Results suggest that the impact of the chemical model is small compared to the influence of the physical conditions, with considered timescales having the most drastic effect. Source-tailored models may be simpler by design; however, likely do not sufficiently constrain the physical and chemical parameters within the global picture of star-forming regions. Generic models with more comprehensive physics may not provide the optimal match to observations of a particular protostellar system, but allow a source to be studied in perspective of other star-forming regions.