1. Spectroscopic patch model for massive stars using PHOEBE II and FASTWIND star
- Author
-
Hugues Sana, Angela Kochoska, Jon O. Sundqvist, Andrej Prša, Michael Abdul-Masih, Joachim Puls, and Kyle E. Conroy
- Subjects
stars ,CONTACT ,FOS: Physical sciences ,Astrophysics ,Astronomy & Astrophysics ,spectroscopic ,01 natural sciences ,Computer Science::Digital Libraries ,rotation ,Spectral line ,Spherical geometry ,massive ,ECLIPSING BINARIES ,SYSTEMS ,0103 physical sciences ,Radiative transfer ,Astrophysics::Solar and Stellar Astrophysics ,SPECTRA ,PRESUPERNOVA EVOLUTION ,close ,010303 astronomy & astrophysics ,Solar and Stellar Astrophysics (astro-ph.SR) ,Line (formation) ,Physics ,Science & Technology ,010308 nuclear & particles physics ,Astrophysics::Instrumentation and Methods for Astrophysics ,Astronomy and Astrophysics ,Radius ,Surface gravity ,CLOSE BINARIES ,Physics::History of Physics ,eclipsing ,Radial velocity ,Stars ,LIGHT ,Astrophysics - Solar and Stellar Astrophysics ,Space and Planetary Science ,Physical Sciences ,ATMOSPHERES ,binaries ,techniques - Abstract
Massive stars play an important role in the mechanical and chemical evolution of galaxies. Understanding the internal processes of these stars is vital to our understanding of their evolution and eventual end products. Deformations from spherical geometry are common for massive stars; however, the tools that are currently available for the study of these systems are almost exclusively one-dimensional. We present a new spectroscopic analysis tool tailored for massive stars that deviate from spherical symmetry. This code (entitled SPAMMS) is a spectroscopic patch model that takes the three-dimensional surface geometry of the system into account to produce spectral profiles at given phases and orientations. In using the Wilson-Devinney-like code PHOEBE in combination with the non local thermodynamic equilibrium (NLTE) radiative transfer code FASTWIND, we created a three-dimensional mesh that represents the surface geometry of our system and we assigned FASTWIND emergent intensity line profiles to each mesh triangle, which take the local parameters such as temperature, surface gravity, and radius into account. These line profiles were then integrated across the visible surface, where their flux contribution and radial velocity are taken into account, thus returning a final line profile for the visible surface of the system at a given phase. We demonstrate that SPAMMS can accurately reproduce the morphology of observed spectral line profiles for overcontact systems. Additionally, we show how line profiles of rapidly-rotating single stars differ when taking rotational distortion into account, and the effects that these can have on the determined parameters. Finally, we demonstrate the code's ability to reproduce the Rossiter-Mclaughlin and Struve-Sahade effects., 10 pages, 10 figures, accepted for publication in A&A
- Published
- 2020