Open AccessModelling the colliding‐winds spectra of the 19‐d WR + OB binary in the massive triple system θ Muscae
Author(s) -
Hill G. M.,
Moffat A. F. J.,
StLouis N.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05694.x
Subject(s) - physics , spectral line , binary number , astrophysics , astronomy , arithmetic , mathematics
High signal‐to‐noise ratio, moderate‐resolution spectra, providing full phase coverage of the 19‐d WC6 + OB binary θ Mus (WR 48, HD 113904), have been obtained and show dramatic variations of the C iii λ5696 emission‐line profile. We have modelled these line profile variations using a purely geometrical model which assumes that the emission arises from two regions, an optically thin spherical shell around the WR star and a cone‐shaped region that partially wraps around the OB star. The cone‐shaped region represents the shock front arising from the collision between the winds of the two stars. This work builds upon our earlier study of WR 42 and WR 79, and uses a completely new code for the modelling, which includes the effects of turbulence. We now find much better agreement between the orbital inclination angles found for these stars with those determined using other methods. The fitting parameters found via modelling the C iii λ5696 profile variations of θ Mus are used to infer that the OB companion most likely has a spectral type of O6V or O7V. The modelling presented here continues to show the exciting promise of a better understanding of WR star fundamental parameters.