TRIDENT: an Infrared Differential Imaging Camera Optimized for the Detection of Methanated Substellar Companions

Abstract

A near-infrared camera in use at the Canada-France-Hawaii Telescope (CFHT) and at the 1.6-m telescope of the Observatoire du Mont-Megantic is described. The camera is based on a Hawaii-1 1024x1024 HgCdTe array detector. Its main feature is to acquire three simultaneous images at three wavelengths across the methane absorption bandhead at 1.6 microns, enabling, in theory, an accurate subtraction of the stellar point spread function (PSF) and the detection of faint close methanated companions. The instrument has no coronagraph and features fast data acquisition, yielding high observing efficiency on bright stars. The performance of the instrument is described, and it is illustrated by laboratory tests and CFHT observations of the nearby stars GL526, Ups And and Chi And. TRIDENT can detect (6 sigma) a methanated companion with delta H = 9.5 at 0.5" separation from the star in one hour of observing time. Non-common path aberrations and amplitude modulation differences between the three optical paths are likely to be the limiting factors preventing further PSF attenuation. Instrument rotation and reference star subtraction improve the detection limit by a factor of 2 and 4 respectively. A PSF noise attenuation model is presented to estimate the non-common path wavefront difference effect on PSF subtraction performance.

arXiv comment41 pages, 16 figures, accepted for publication in PASP

References in corpus (10)

• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• Stellar Companions to Stars with Planets
• Imaging Spectroscopy for Extrasolar Planet Detection
• Discovery of a Brown Dwarf Companion to Gliese 570ABC: A 2MASS T Dwarf Significantly Cooler than Gliese 229B
• A search for hot massive extrasolar planets around nearby young stars with the adaptive optics system NACO
• The Structure of High Strehl Ratio Point-Spread Functions
• Coronagraphic Survey for Companions of Stars within 8 pc
• An Adaptive Optics Search for Companions to Stars with Planets
• Differential Imaging with a Multicolor Detector Assembly: A New ExoPlanet Finder Concept
• Effects of Quasi-Static Aberrations in Faint Companion Searches

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