S4: A Spatial-Spectral model for Speckle Suppression

Abstract

High dynamic-range imagers aim to block out or null light from a very bright primary star to make it possible to detect and measure far fainter companions; in real systems a small fraction of the primary light is scattered, diffracted, and unocculted. We introduce S4, a flexible data-driven model for the unocculted (and highly speckled) light in the P1640 spectroscopic coronograph. The model uses Principal Components Analysis (PCA) to capture the spatial structure and wavelength dependence of the speckles but not the signal produced by any companion. Consequently, the residual typically includes the companion signal. The companion can thus be found by filtering this error signal with a fixed companion model. The approach is sensitive to companions that are of order a percent of the brightness of the speckles, or up to $10^{-7}$ times the brightness of the primary star. This outperforms existing methods by a factor of 2-3 and is close to the shot-noise physical limit.

accepted for publication in ApJ

References in corpus (14)

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• A Data Cube Extraction Pipeline for a Coronagraphic Integral Field Spectrograph
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• Astrometric Monitoring of the HR 8799 Planets: Orbit Constraints from Self-Consistent Measurements
• The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Super-Stellar Metallicity
• Supervised detection of exoplanets in high-contrast imaging sequences
• Direct Spectrum of the Benchmark T dwarf HD 19467 B
• Project 1640 Observations of Brown Dwarf GJ 758 B: Near-Infrared Spectrum and Atmospheric Modeling
• A New Method for Characterizing Very-Low-Mass Companions with Low Resolution Near-Infrared Spectroscopy
• Pushing the Limits of Exoplanet Discovery via Direct Imaging with Deep Learning
• A deep search for planets in the inner 15 au around Vega
• Archival Legacy Investigations of Circumstellar Environments (ALICE): Statistical assessment of point source detections
• Project 1640 Observations of the White Dwarf HD 114174 B
• Reduced Order Estimation of the Speckle Electric Field History for Space-Based Coronagraphs