VLTI-AMBER velocity-resolved aperture-synthesis imaging of η Carinae with a spectral resolution of 12 000. Studies of the primary star wind and innermost wind-wind collision zone
Context. The mass loss from massive stars is not understood well.
Aims: We want to investigate the structure and kinematics of η Car's primary star wind and wind-wind collision zone with a high spatial resolution of ~6 mas (~14 au) and high spectral resolution of R = 12 000.
Methods: Observations of
Results: We present velocity-resolved aperture-synthesis images reconstructed in more than 100 different spectral channels distributed across the Brγ 2.166 μm emission line. The intensity distribution of the images strongly depends on wavelength. At wavelengths corresponding to radial velocities of approximately -140 to - 376 km s-1 measured relative to line center, the intensity distribution has a fan-shaped structure. At the velocity of - 277 km s-1, the position angle of the symmetry axis of the fan is ~126°. The fan-shaped structure extends approximately 8.0 mas (~18.8 au) to the southeast and 5.8 mas (~13.6 au) to the northwest, measured along the symmetry axis at the 16% intensity contour. The shape of the intensity distributions suggests that the obtained images are the first direct images of the innermost wind-wind collision zone. Therefore, the observations provide velocity-dependent image structures that can be used to test three-dimensional hydrodynamical, radiative transfer models of the massive interacting winds of η Car. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO program 092.D-0289(A).The reconstructed digital images are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://22.214.171.124) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/594/A106
Astronomy and Astrophysics
- Pub Date:
- October 2016
- stars: winds;
- stars: individual: ηCarinae;
- stars: massive;
- stars: mass-loss;
- binaries: general;
- techniques: interferometric;
- Astrophysics - Solar and Stellar Astrophysics