The Giant Accreting Protoplanet Survey (GAPlanetS): Optimization Techniques for Robust Detections of Protoplanets

Jéa I. Adams Redai; Katherine B. Follette; Jason Wang; Clare Leonard; William Balmer; Laird M. Close; Beck Dacus; Jared R. Males; Katie M. Morzinski; Joseph Palmo; Laurent Pueyo; Elijah Spiro; Helena Treiber; Kimberly Ward-Duong; Alex Watson

doi:10.3847/1538-3881/aca60d

The Astronomical Journal (Jan 2023)

The Giant Accreting Protoplanet Survey (GAPlanetS): Optimization Techniques for Robust Detections of Protoplanets

Jéa I. Adams Redai,
Katherine B. Follette,
Jason Wang,
Clare Leonard,
William Balmer,
Laird M. Close,
Beck Dacus,
Jared R. Males,
Katie M. Morzinski,
Joseph Palmo,
Laurent Pueyo,
Elijah Spiro,
Helena Treiber,
Kimberly Ward-Duong,
Alex Watson

Affiliations

Jéa I. Adams Redai: ORCiD; Center for Astrophysics ∣Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USA ; [email protected]; Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA
Katherine B. Follette: ORCiD; Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA
Jason Wang: ORCiD; Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
Clare Leonard: Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA; Epic Systems , 1979 Milky Way, Verona, WI 53593, USA
William Balmer: ORCiD; Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA; Department of Physics & Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore MD 21218, USA
Laird M. Close: ORCiD; Steward Observatory, University of Arizona , Tucson, AZ 85721, USA
Beck Dacus: Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA
Jared R. Males: ORCiD; Steward Observatory, University of Arizona , Tucson, AZ 85721, USA
Katie M. Morzinski: ORCiD; Steward Observatory, University of Arizona , 933 N. Cherry Avenue, Tucson, AZ 85721, USA
Joseph Palmo: Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA
Laurent Pueyo: ORCiD; Department of Physics & Astronomy, Johns Hopkins University , 3400 N. Charles Street, Baltimore, MD 21218, USA; Space Telescope Science Institute , 3700 San Martin Drive, Baltimore MD 21218, USA
Elijah Spiro: Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA; NASA Kennedy Space Center , NASA Kennedy Space Center, Fl, 32899, USA
Helena Treiber: ORCiD; Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA
Kimberly Ward-Duong: ORCiD; Department of Astronomy , Smith College, Northampton, MA 01063 USA
Alex Watson: Amherst College Department of Physics and Astronomy , PO Box 5000, Amherst, MA 01002-5000, USA

DOI: https://doi.org/10.3847/1538-3881/aca60d
Journal volume & issue: Vol. 165, no. 2
p. 57

Abstract

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High-contrast imaging has afforded astronomers the opportunity to study light directly emitted by adolescent (tens of megayears) and “proto” (<10 Myr) planets still undergoing formation. Direct detection of these planets is enabled by empirical point-spread function (PSF) modeling and removal algorithms. The computational intensity of such algorithms, as well as their multiplicity of tunable input parameters, has led to the prevalence of ad hoc optimization approaches to high-contrast imaging results. In this work, we present a new, systematic approach to optimization vetted using data of the high-contrast stellar companion HD 142527 B from the Magellan Adaptive Optics Giant Accreting Protoplanet Survey (GAPlanetS). More specifically, we present a grid search technique designed to explore three influential parameters of the PSF subtraction algorithm pyKLIP : annuli, movement, and KL modes. We consider multiple metrics for postprocessed image quality in order to optimally recover at H α (656 nm) synthetic planets injected into contemporaneous continuum (643 nm) images. These metrics include peak (single-pixel) signal-to-noise ratio (S/N), average (multipixel average) S/N, 5 σ contrast, and false-positive fraction. We apply continuum-optimized KLIP reduction parameters to six H α direct detections of the low-mass stellar companion HD 142527 B and recover the companion at a range of separations. Relative to a single-informed, nonoptimized set of KLIP parameters applied to all data sets uniformly, our multimetric grid search optimization led to improvements in companion S/N of up to 1.2 σ , with an average improvement of 0.6 σ . Since many direct imaging detections lie close to the canonical 5 σ threshold, even such modest improvements may result in higher yields in future imaging surveys.

Published in The Astronomical Journal

ISSN: 0004-6256 (Print); 1538-3881 (Online)
Publisher: IOP Publishing
Country of publisher: United Kingdom
LCC subjects: Science: Astronomy
Website: https://iopscience.iop.org/journal/1538-3881

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