The solar type protostar IRAS16293-2422: new constraints on the physical structure

TL;DR

This study refines the physical structure of the protostar IRAS16293-2422 by analyzing continuum and water data, supporting an inside-out collapse model and providing a basis for chemical structure studies.

Contribution

It offers a detailed physical model of IRAS16293-2422's envelope, reconciling previous discrepancies and aiding chemical analysis of this protostar.

Findings

Envelope fits Shu 'inside-out' collapse model

No evidence of a large cavity in the envelope

Provides temperature and density profiles for chemical modeling

Abstract

Context: The low mass protostar IRAS16293-2422 is a prototype Class 0 source with respect to the studies of the chemical structure during the initial phases of life of Solar type stars. Aims: In order to derive an accurate chemical structure, a precise determination of the source physical structure is required. The scope of the present work is the derivation of the structure of IRAS16293-2422. Methods: We have re-analyzed all available continuum data (single dish and interferometric, from millimeter to MIR) to derive accurate density and dust temperature profiles. Using ISO observations of water, we have also reconstructed the gas temperature profile. Results: Our analysis shows that the envelope surrounding IRAS16293-2422 is well described by the Shu "inside-out" collapsing envelope model or a single power-law density profile with index equal to 1.8. In contrast to some previous studies, our analysis does not show evidence of a large (>/- 800 AU in diameter) cavity. Conclusions: Although IRAS16293-2422 is a multiple system composed by two or three objects, our reconstruction will be useful to derive the chemical structure of the large cold envelope surrounding these objects and the warm component, treated here as a single source, from single-dish observations of molecular emission.