Numerical simulations and infrared spectro-interferometry reveal the wind collision region in gamma2 Velorum
Date Issued
2017
Author(s)
Lamberts, A.
•
Millour, F.
•
Liermann, A.
•
Dessart, L.
•
Driebe, T.
•
Duvert, G.
•
Finsterle, W.
•
Girault, V.
•
•
Petrov, R. G.
•
Schmutz, W.
•
Weigelt, G.
•
Chesneau, O.
Abstract
Colliding stellar winds in massive binary systems have been studied through
their radio, optical lines and strong X-ray emission for decades. More
recently, near-infrared spectrointerferometric observations have become
available in a few systems, but isolating the contribution from the individual
stars and the wind collision region still remains a challenge. In this paper,
we study the colliding wind binary gamma2 Velorum and aim at identifying the
wind collision zone from infrared interferometric data, which provide unique
spatial information to determine the wind properties. Our analysis is based on
multi-epoch VLTI/AMBER data that allows us to separate the spectral components
of both stars. First, we determine the astrometric solution of the binary and
confirm previous distance measurements. We then analyse the spectra of the
individual stars, showing that the O star spectrum is peculiar within its
class. Then, we perform three-dimensional hydrodynamic simulations of the
system from which we extract model images, visibility curves and closure phases
which can be directly compared with the observed data. The hydrodynamic
simulations reveal the 3D spiral structure of the wind collision region, which
results in phase-dependent emission maps. Our model visibility curves and
closure phases provide a good match when the wind collision region accounts for
3 to 10 per cent of the total flux in the near infrared. The dialogue between
hydrodynamic simulations, radiative transfer models and observations allows us
to fully exploit the observations. Similar efforts will be crucial to study
circumstellar environments with the new generation of VLTI instruments like
GRAVITY and MATISSE.
Volume
468
Issue
3
Start page
2655
Issn Identifier
0035-8711
Ads BibCode
2017MNRAS.468.2655L
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
fmassi2017.pdf
Description
Pdf editoriale
Size
4.26 MB
Format
Adobe PDF
Checksum (MD5)
920942733cf0ad676181409f0e598359