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The CHARIS High-Contrast Integral-Field SpectrographOne of the leading direct Imaging techniques, particularly in ground-based imaging, uses a coronagraphic system and integral field spectrograph (IFS). The Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) is an IFS that has been built for the Subaru telescope. CHARIS has been delivered to the observatory and now sits behind the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. CHARIS has 'high' and 'low' resolution operating modes. The "high-resolution" mode is used to characterize targets in J, H, and K bands at ~R70. The "low-resolution" prism is meant for discovery and spans J+H+K bands (1.15-2.37 microns) with a spectral resolution of ~R18. This discovery mode has already proven better than 15-sigma detections of HR8799c,d,e when combining ADI+SDI. Using SDI alone, planets c and d have been detected in a single 24 second image. The CHARIS team is optimizing instrument performance and refining ADI+SDI recombination to maximize our contrast detection limit. In addition to the new observing modes, CHARIS has demonstrated a design with high robustness to spectral crosstalk. CHARIS is in the final stages of commissioning, with the instrument open for science observations beginning February 2017. Here we review the science case, design, on-sky performance, engineering observations of exoplanet and disk targets, and specific lessons learned for extremely high contrast imagers. Key design aspects that will be demonstrated are crosstalk optimization, wavefront correction using the IFS image, lenslet tolerancing, the required spectral resolution to fit exoplanet atmospheres, and the utility of the spectrum in achieving higher contrast detection limits.
Document ID
20180000766
Acquisition Source
Goddard Space Flight Center
Document Type
Presentation
Authors
Groff, Tyler D.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chilcote, Jeffrey
(Toronto Univ. Ontario, Canada)
Brandt, Timothy
(Institute for Advanced Study Princeton, NJ, United States)
Kasdin, N. Jeremy
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Galvin, Michael
(Princeton Univ. Princeton, NJ, United States)
Loomis, Craig
(Princeton Univ. Princeton, NJ, United States)
Rizzo, Maxime
(Universities Space Research Association Greenbelt, MD, United States)
Knapp, Gillian
(Princeton Univ. Princeton, NJ, United States)
Guyon, Olivier
(Tokyo Astronomical Observatory Mitaka, Japan)
Jovanovic, Nemanja
(Tokyo Astronomical Observatory Mitaka, Japan)
Lozi, Julien
(Subaru Telescope Hilo, HI, United States)
Takato, Naruhisa
(Tokyo Astronomical Observatory Mitaka, Japan)
Hayashi, Masahiko
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
January 25, 2018
Publication Date
December 15, 2017
Subject Category
Instrumentation And Photography
Astronomy
Report/Patent Number
GSFC-E-DAA-TN50180
Report Number: GSFC-E-DAA-TN50180
Meeting Information
Meeting: CHARIS International Workshop 2017
Location: Tokyo
Country: Japan
Start Date: December 15, 2017
End Date: December 17, 2017
Sponsors: Tokyo Astronomical Observatory
Funding Number(s)
CONTRACT_GRANT: NNN12AA01C
Distribution Limits
Public
Copyright
Portions of document may include copyright protected material.
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