CHARIS

Science &Data Extraction Software

Kyle Mede

November 18th

Key Collaborators: Tim Brandt, Mike McElwain, Tyler Groff and Mary Anne Peters

2

N. Jeremy Kasdin (instrument PI), Tyler D. Groff, Mary Anne Peters, Michael Galvin, Michael Carr, Norman Jarosik

Craig Loomis, Robert Lupton

Gillian Knapp, Michael McElwain, Timothy Brandt, Markus Janson, James E. Gunn

Princeton University

Olivier Guyon, Nemanja Jovanovic, Naruhisa Takato, Frantz Martinache

Subaru Telescope

Kyle Mede, Motohide Tamura

University of Tokyo, Todai

Masahiko Hayashi (project PI)

National Astronomical Observatory of Japan

Reviewers: James Lloyd, Bruce Macintosh, Klaus Hodapp, Harvey Moseley

The CHARIS High-Contrast Imaging Spectrograph

Overview

CHARIS Overview ADI -> SDI IFS advantages Improvements thanks to CHARIS CHARIS science Data Extraction Pipeline Status

Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS)

CHARIS is an Integral Field Spectrograph (IFS) being built for Subaru to directly image and characterize exoplanets and brown dwarf companions, along with the inner regions of circumstellar disks.

Specs:

CHARIS: IFSCore benefit:

Simultaneous spacial (x,y) and spectral (λ) data, saving telescope time and allowing for better speckle suppression

CHARIS: LayoutCoronagraphy and AO done with AO188 and SCExAO, then

corrected light is fed to CHARIS

An IFS provides both spacial and spectral information simultaneously. This allows for

advanced algorithms that suppress speckles and improve contrast ratios in the reduced data.

Angular Differential Imaging (ADI)

Spectral Differential Imaging (SDI): 1Take advantage of the fact that planetary objects have large

intrinsic molecular features in their spectrum, while host star's spectra are relatively flat (Vigan 2010).

Brandner 2012

SDI: 2

SDI+ADI is capable of 1.5-2.5 mag higher contrast than ADI alone (Vigan 2010).

Additional IFS Advantages

Classical SDI of (Marois 2000, Vigan 2010...) only utilizes ~2 narrow band images, Berton 2006 shows that using many molecular features from IFS data can further enhance S/N.

Thanks to the LBBH glass, simultaneous J-K observations provide ~2x coverage to fully exploit SDI down to ~0.1” separations, compared to other IFSs (SPHERE, GPI, Project1640).

Stellar PSF scales linearly with while a nearby faint point source stay in same position. A 2D model can be fit and subtracted from 3D data to improve contrast.

Brandt et al.SPIE 2013

Simulated Data Cube

Completeness Improvements: 1

Completeness Improvements: 2

Science and Characterization Low resolution spectra can help distinguish planetary from stellar companions. This capability is absolutely essential to all exoplanet investigations!

Data Extraction Pipeline (DEP): Goal

To compose a pipeline that will automatically process the data from the CHARIS instrument resulting in a fully

calibrated 3D data cube

Extraction Flow

Status

Critical Design Review for CHARIS completed Dec 7

Building underway, receiving lots of hardware, including all of the foreoptics from L-3, L-BBH2 testing...

Initial DEP software design done, briefly reviewed and under development. Key focus at the moment is proof of concept for our new approaches to data extraction.

Code storage, documentation, versioning, debugging... decided and initialized

Instrument simulator nearing completion

Although finalizing it is now a bit ...

Anyone want a job translating Matlab-Python :-p

End Any Questions?