Infrared Imaging of Capella with the IOTA Interferometer

摘要

We present near infrared aperture synthesis maps of the well known binary star Capella (α Aur) produced with the upgraded IOTA interferometer on top of Mount Hopkins, Arizona. Michelson interferograms were obtained simultaneously on three interferometer baselines in the H-band between 2002 November 12 and 16. The simultaneous observation of fringes on three baselines permitted a single phase closure to be estimated along with three visibility amplitudes. Hybrid Mapping techniques were then used to reconstruct the source brightness distribution with a beam size of (5.4 x 2.6) mas, which allows for the resolution of the stellar surfaces of the Capella giants. The maps provide the first demonstration of imaging with phase closure on the IOTA instrument.