The vector vortex is a coronagraphic imaging mode of the recently commissioned Subaru Coronagraphic Extreme-Adaptive Optics (SCExAO) platform on the 8-m Subaru Telescope. This multi-purpose high-contrast visible and near-infrared (R- to K-band) instrument is not only intended to serve as a VLT-class "planet-imager" instrument in the Northern hemisphere, but also to operate as a technology demonstration testbed ahead of the ELTs-era, with a particular emphasis on small inner-working angle (IWA) coronagraphic capabilities. The given priority to small-IWA imaging led to the early design choice to incorporate focal-plane phase-mask coronagraphs. In this context, a test H-band vector vortex liquid crystal polymer waveplate was provided to SCExAO, to allow a one-to-one comparison of different small-IWA techniques on the same telescope instrument, before considering further steps. Here we present a detailed overview of the vector vortex coronagraph, from its installation and performances on the SCExAO optical bench, to the on-sky results in the extreme AO regime, as of late 2016/early 2017. To this purpose, we also provide a few recent on-sky imaging examples, notably high-contrast ADI detection of the planetary-mass companion \kappa Andromedae b, with a signal-to-noise ratio above 100 reached in less than 10 mn exposure time.
@article{arxiv.1712.02040,
title = {An H-band Vector Vortex Coronagraph for the Subaru Coronagraphic Extreme-Adaptive Optics System},
author = {Jonas Kühn and Eugene Serabyn and Julien Lozi and Nemanja Jovanovic and Thayne Currie and Olivier Guyon and Tomoyuki Kudo and Frantz Martinache and Kurt Liewer and Garima Singh and Motohide Tamura and Dimitri Mawet and Janis Hagelberg and Denis Defrère},
journal= {arXiv preprint arXiv:1712.02040},
year = {2018}
}
Comments
25 pages, 8 figures, accepted for publication in Publications of the Astronomical Society of the Pacific (PASP)