A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data
AuthorGerard, Benjamin L.
Chilcote, Jeffrey K.
Draper, Zachary H.
Knapp, Gillian R.
AffiliationUniv Arizona, Steward Observ
Keywordstechniques: high angular resolution
techniques: image processing
planets and satellites: general
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationBenjamin L. Gerard et al 2019 AJ 158 36
RightsCopyright © 2019. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractWe present an analysis of instrument performance using new observations taken with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS) instrument and the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. In a correlation analysis of our data sets (which use the broadband mode covering the J band through the K band in a single spectrum), we find that chromaticity in the SCExAO/CHARIS system is generally worse than temporal stability. We also develop a point-spread function (PSF) subtraction pipeline optimized for the CHARIS broadband mode, including a forward modeling-based exoplanet algorithmic throughput correction scheme. We then present contrast curves using this newly developed pipeline. An analogous subtraction of the same data sets using only the H-band slices yields the same final contrasts as the full JHK sequences; this result is consistent with our chromaticity analysis, illustrating that PSF subtraction using spectral differential imaging (SDI) in this broadband mode is generally not more effective than SDI in the individual J, H, or K bands. In the future, the data processing framework and analysis developed in this paper will be important to consider for additional SCExAO/CHARIS broadband observations and other ExAO instruments which plan to implement a similar integral field spectrograph broadband mode.
VersionFinal published version
SponsorsNatural Sciences and Engineering Council of Canada through the Postgraduate Scholarships-Doctoral discovery grant; Technologies for Exo-Planetary Science Collaborative Research and Training Experience programs; JSPS [23340051, 26220704, 23103002]; Astrobiology Center of the National Institutes of Natural Sciences, Japan; Mt. Cuba Foundation; directors contingency fund at Subaru Telescope; MEXT of the Japanese government