Bibcode
Thompson, Samantha; Doel, Andrew P.; Bingham, Richard G.; Charalambous, Andrew; Bissonauth, Nirmal; Clark, Paul; Myers, Richard M.; Talbot, Gordon
Referencia bibliográfica
Adaptive Optical System Technologies II. Edited by Wizinowich, Peter L.; Bonaccini, Domenico. Proceedings of the SPIE, Volume 4839, pp. 1085-1092 (2003).
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2
2003
Número de citas
2
Número de citas referidas
2
Descripción
We describe a coronagraph facility built for use with the 4.2 metre
William Herschel Telescope (WHT) and its adaptive optics system (NAOMI).
The use of the NAOMI adaptive optics system gives an improved image
resolution of ~0.15 arcsec at a wavelength of 2.2 microns. This enables
our Optimised Stellar Coronagraph for Adaptive optics (OSCA) to null
stellar light with smaller occulting masks and thus allows regions
closer to bright astronomical objects to be imaged. OSCA is a fully
deployable instrument and when in use leaves the focus of the NAOMI beam
unchanged. This enables OSCA to be used in conjunction with a number of
instruments already commissioned at the WHT. The main imaging camera to
be used with OSCA will be INGRID; a 1024×1024 HgCdTe cooled SWIR
detector at the NAOMI focus. OSCA can also be used in conjunction with
an integral field spectrograph for imaging at visible wavelengths. OSCA
provides a selection of 10 different occulting mask sizes from 0.25 -
2.0 arcsec and some with a novel gaussian profile. There is also a
choice of 2 different Lyot stops (pupil plane masks). A dichroic placed
before the AO system can give us improved nulling when occulting masks
larger than the seeing disk are used. We also present results from
initial testing and commissioning at the William Herschel Telescope.