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Laboratory and On-Sky Validation of the Shaped Pupil Coronagraph's Sensitivity to Low-Order Aberrations with Active Wavefront ControlWe present early laboratory simulations and extensive on-sky tests validating of the performance of a shaped pupil coronagraph (SPC) behind an extreme-AO (Adaptive Optics) corrected beam of the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system. In tests with the SCExAO internal source/wavefront error simulator, the normalized intensity profile for the SPC degrades more slowly than for the Lyot coronagraph as low-order aberrations reduce the Strehl ratio (S.R.) from extremely high values (S.R. approximately 0.93-0.99) to those characteristic of current ground-based extreme AO systems (S.R. approximately 0.74-0.93) and then slightly lower values down to S.R. approximately 0.57. On-sky SCExAO data taken with the SPC and other coronagraphs for brown dwarf/planet-hosting stars HD 1160 and HR 8799 provide further evidence for the SPC's robustness to low-order aberrations. From H-band Strehl ratios of 80 percent to 70 percent, the Lyot coronagraph's performance versus that of the SPC may degrade even faster on sky than is seen in our internal source simulations. The 5-sigma contrast also degrades faster (by a factor of two) for the Lyot than the SPC. The SPC we use was designed as a technology demonstrator only, with a contrast floor, throughput, and outer working angle poorly matched for SCExAO's current AO performance and poorly tuned for imaging the HR 8799 planets. Nevertheless, we detect HR 8799 cde with SCExAO/CHARIS using the SPC in broadband mode, where the signal-to-noise ratio for planet e is within 30 percent of that obtained using the vortex coronagraph. The shaped-pupil coronagraph is a promising design demonstrated to be robust in the presence of low-order aberrations and may be well-suited for future ground and space-based direct imaging observations, especially those focused on follow-up exoplanet characterization and technology demonstration of deep contrast within well-defined regions of the image plane.
Document ID
20180003025
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Currie, Thayne
(Subaru Telescope Hilo, HI, United States)
Kasdin, N. Jeremy
(Princeton Univ. NJ, United States)
Groff, Tyler D.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Lozi, Julien
(Subaru Telescope Hilo, HI, United States)
Jovanovic, Nemanja
(Subaru Telescope Hilo, HI, United States)
Guyon, Olivier
(Subaru Telescope Hilo, HI, United States)
Brandt, Timothy
(California Univ. Santa Barbara, CA, United States)
Martinache, Frantz
(Observatoire de la Cote d'Azur Nice, France)
Chilcote, Jeffrey
(Stanford Univ. Palo Alto, CA, United States)
Skaf, Nour
(Subaru Telescope Hilo, HI, United States)
Kuhn, Jonas
(Eidgenossische Technische Hochschule Zurich, Switzerland)
Pathak, Prashant
(Subaru Telescope Hilo, HI, United States)
Kudo, Tomoyuki
(Subaru Telescope Hilo, HI, United States)
Date Acquired
May 25, 2018
Publication Date
March 13, 2018
Publication Information
Publication: Publications of the Astronomical Society of the Pacific
Publisher: IOP Science
Volume: 130
Issue: 986
ISSN: 0004-6280
e-ISSN: 1538-3873
Subject Category
Instrumentation And Photography
Astronomy
Report/Patent Number
GSFC-E-DAA-TN56122
Funding Number(s)
OTHER: 2018-551-WFIRST
Distribution Limits
Public
Copyright
Other

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