Towards Understanding The B[e] Phenomenon: IV. Modeling of IRAS 00470+6429

TL;DR

This paper presents a detailed physical model of IRAS 00470+6429, a B[e] phenomenon star, successfully reproducing its spectral features and dust properties by assuming a bimodal wind structure and a novel dust formation approach.

Contribution

It introduces a new modeling approach for B[e] stars that incorporates a bimodal wind structure and a self-consistent dust formation process, improving understanding of their circumstellar environments.

Findings

Successfully reproduces spectral energy distribution and H line profiles.

Demonstrates the effectiveness of a bimodal wind model for B[e] stars.

Provides insights into dust formation and destruction in circumstellar envelopes.

Abstract

FS CMa type stars are a recently described group of objects with the B[e] phenomenon that exhibit strong emission-line spectra and strong IR excesses. In this paper we report the first attempt for a detailed modeling of IRAS 00470+6429, for which we have the best set of observations. Our modeling is based on two key assumptions: the star has a main-sequence luminosity for its spectral type (B2) and the circumstellar envelope is bimodal, composed of a slowly outflowing disk-like wind and a fast polar wind. Both outflows are assumed to be purely radial. We adopt a novel approach to describe the dust formation site in the wind that employs timescale arguments for grain condensation and a self-consistent solution for the dust destruction surface. With the above assumptions we were able to reproduce satisfactorily many observational properties of IRAS 00470+6429, including the H line profiles and the overall shape of the spectral energy distribution. Our adopted recipe for dust formation proved successful in reproducing the correct amount of dust formed in the circumstellar envelope. Possible shortcomings of our model, as well as suggestions for future improvements, are discussed.