A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data

Benjamin L. Gerard, Christian Marois, Thayne Currie, Timothy Brandt, Jeffrey K. Chilcote, Zachary H. Draper, Tyler Groff, Olivier Guyon, Masahiko Hayashi, Nemanja Jovanovic, Gillian R. Knapp, Tomoyuki Kudo, Jungmi Kwon, Julien Lozi, Frantz Martinache, Michael McElwain, Motohide Tamura, Taichi Uyama

Research output: Contribution to journalArticle

Abstract

We 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.

Original languageEnglish (US)
Article number36
JournalAstronomical Journal
Volume158
Issue number1
DOIs
StatePublished - Jan 1 2019

Fingerprint

point spread functions
angular resolution
adaptive optics
subtraction
spectrographs
broadband
high resolution
extremely high frequencies
forward modeling
extrasolar planets
coverings
analysis
curves

Keywords

  • planets and satellites: general
  • techniques: high angular resolution
  • techniques: image processing

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gerard, B. L., Marois, C., Currie, T., Brandt, T., Chilcote, J. K., Draper, Z. H., ... Uyama, T. (2019). A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data. Astronomical Journal, 158(1), [36]. https://doi.org/10.3847/1538-3881/ab21d4

A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data. / Gerard, Benjamin L.; Marois, Christian; Currie, Thayne; Brandt, Timothy; Chilcote, Jeffrey K.; Draper, Zachary H.; Groff, Tyler; Guyon, Olivier; Hayashi, Masahiko; Jovanovic, Nemanja; Knapp, Gillian R.; Kudo, Tomoyuki; Kwon, Jungmi; Lozi, Julien; Martinache, Frantz; McElwain, Michael; Tamura, Motohide; Uyama, Taichi.

In: Astronomical Journal, Vol. 158, No. 1, 36, 01.01.2019.

Research output: Contribution to journalArticle

Gerard, BL, Marois, C, Currie, T, Brandt, T, Chilcote, JK, Draper, ZH, Groff, T, Guyon, O, Hayashi, M, Jovanovic, N, Knapp, GR, Kudo, T, Kwon, J, Lozi, J, Martinache, F, McElwain, M, Tamura, M & Uyama, T 2019, 'A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data', Astronomical Journal, vol. 158, no. 1, 36. https://doi.org/10.3847/1538-3881/ab21d4
Gerard BL, Marois C, Currie T, Brandt T, Chilcote JK, Draper ZH et al. A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data. Astronomical Journal. 2019 Jan 1;158(1). 36. https://doi.org/10.3847/1538-3881/ab21d4
Gerard, Benjamin L. ; Marois, Christian ; Currie, Thayne ; Brandt, Timothy ; Chilcote, Jeffrey K. ; Draper, Zachary H. ; Groff, Tyler ; Guyon, Olivier ; Hayashi, Masahiko ; Jovanovic, Nemanja ; Knapp, Gillian R. ; Kudo, Tomoyuki ; Kwon, Jungmi ; Lozi, Julien ; Martinache, Frantz ; McElwain, Michael ; Tamura, Motohide ; Uyama, Taichi. / A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data. In: Astronomical Journal. 2019 ; Vol. 158, No. 1.
@article{3dd80495442340438f813743276a9372,
title = "A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data",
abstract = "We 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.",
keywords = "planets and satellites: general, techniques: high angular resolution, techniques: image processing",
author = "Gerard, {Benjamin L.} and Christian Marois and Thayne Currie and Timothy Brandt and Chilcote, {Jeffrey K.} and Draper, {Zachary H.} and Tyler Groff and Olivier Guyon and Masahiko Hayashi and Nemanja Jovanovic and Knapp, {Gillian R.} and Tomoyuki Kudo and Jungmi Kwon and Julien Lozi and Frantz Martinache and Michael McElwain and Motohide Tamura and Taichi Uyama",
year = "2019",
month = "1",
day = "1",
doi = "10.3847/1538-3881/ab21d4",
language = "English (US)",
volume = "158",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - A Chromaticity Analysis and PSF Subtraction Techniques for SCExAO/CHARIS Data

AU - Gerard, Benjamin L.

AU - Marois, Christian

AU - Currie, Thayne

AU - Brandt, Timothy

AU - Chilcote, Jeffrey K.

AU - Draper, Zachary H.

AU - Groff, Tyler

AU - Guyon, Olivier

AU - Hayashi, Masahiko

AU - Jovanovic, Nemanja

AU - Knapp, Gillian R.

AU - Kudo, Tomoyuki

AU - Kwon, Jungmi

AU - Lozi, Julien

AU - Martinache, Frantz

AU - McElwain, Michael

AU - Tamura, Motohide

AU - Uyama, Taichi

PY - 2019/1/1

Y1 - 2019/1/1

N2 - We 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.

AB - We 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.

KW - planets and satellites: general

KW - techniques: high angular resolution

KW - techniques: image processing

UR - http://www.scopus.com/inward/record.url?scp=85072370179&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85072370179&partnerID=8YFLogxK

U2 - 10.3847/1538-3881/ab21d4

DO - 10.3847/1538-3881/ab21d4

M3 - Article

AN - SCOPUS:85072370179

VL - 158

JO - Astronomical Journal

JF - Astronomical Journal

SN - 0004-6256

IS - 1

M1 - 36

ER -