Three Dimensional Radiative Transfer in Winds of Massive Stars: Wind3D

TL;DR

Wind3D is a new 3D radiative transfer code that accurately models line formation in complex stellar winds, enabling detailed analysis of ultraviolet P Cygni profiles in massive stars.

Contribution

The paper introduces Wind3D, a fully parallelized 3D radiative transfer code capable of handling arbitrary velocity fields without symmetry assumptions.

Findings

Accurately models P Cygni line profiles in UV spectra.

Handles complex velocity fields and clumping effects.

Provides detailed insights into wind structure and line formation.

Abstract

We discuss the development of the new radiative transfer code Wind3D. It solves the non-LTE radiative transport problem in moving stellar atmosphere models in three geometric dimensions. The code accepts arbitrary 3D velocity fields in Cartesian geometry without assumptions of axial symmetry. Wind3D is currently implemented as a fully parallelized (exact) accelerated lambda iteration scheme with a two level atom formulation. The numerical transfer scheme is efficient and very accurate to trace small variations of local velocity gradients on line opacity in strongly scattering dominated extended stellar winds. We investigate the detailed formation of P Cygni line profiles observed in ultraviolet spectra of massive stars. We compute the detailed shape of these resonance lines to model local enhancements of line opacity that can for instance be caused by clumping in supersonically expanding winds. Wind3D will be applied to hydrodynamic models to investigate physical properties of discrete absorption line components.