eta Car velocity-resolved imaging

It is also an eccentric binary with a period of 5.54yr. The nature of both stars is uncertain, although we know from X-ray studies that there is a wind-wind collision whose properties change with orbital phase.

We want to investigate the structure and kinematics of eta Car's primary star wind and wind-wind collision zone with a high spatial resolution of ~6mas (~14au) and high spectral resolution of R=12000. Observations of eta Car were carried out with the ESO Very Large Telescope Interferometer (VLTI) and the AMBER instrument between approximately five and seven months before the August 2014 periastron passage. Velocity-resolved aperture-synthesis images were reconstructed from the spectrally dispersed interferograms.