Models of Rotating Infall for the B335 Protostar

TL;DR

This paper develops advanced 3D models of the B335 protostar, integrating extensive observational data to better understand its infall, rotation, and evolutionary stage, revealing a possible pseudo-disk component.

Contribution

It introduces a comprehensive 3D radiative transfer model constrained by multi-wavelength observations, resolving previous conflicts in age estimates and continuum emission predictions.

Findings

Models favor collapse ages of 30,000 to 40,000 years.

Under-predict continuum emission, indicating a possible pseudo-disk.

Luminosity varied by a factor of 5-7 over 8 years.

Abstract

Models of the protostellar source, B335, are developed using axisymmetric three-dimensional models to resolve conflicts found in one-dimensional models. The models are constrained by a large number of observations, including ALMA, Herschel, and Spitzer data. Observations of the protostellar source B335 with ALMA show red-shifted absorption against a central continuum source indicative of infall in the HCO$^+$ and HCN $J = 4\rightarrow 3$ transitions. The data are combined with a new estimate of the distance to provide strong constraints to three-dimensional radiative transfer models including a rotating, infalling envelope, outflow cavities, and a very small disk. The models favor ages since the initiation of collapse between $3 \times 10^4$ and $4 \times 10^4$ yr for both the continuum and the lines, resolving a conflict found in one-dimensional models. The models under-predict the continuum emission seen by ALMA, suggesting an additional component such as a pseudo-disk. The best-fitting model is used to convert variations in the 4.5 $\mu m$ flux in recent years into a model for a variation of a factor of 5-7 in luminosity over the last 8 years.