GPI PSF subtraction with TLOCI: the next evolution in exoplanet/disk high-contrast imaging

Abstract

To directly image exoplanets and faint circumstellar disks, the noisy stellar halo must be suppressed to a high level. To achieve this feat, the angular differential imaging observing technique and the least-squares Locally Optimized Combination of Images (LOCI) algorithm have now become the standard in single band direct imaging observations and data reduction. With the development and commissioning of new high-order high-contrast adaptive optics equipped with integral field units, the image subtraction algorithm needs to be modified to allow the optimal use of polychromatic images, field-rotated images and archival data. A new algorithm, TLOCI (for Template LOCI), is designed to achieve this task by maximizing a companion signal-to-noise ratio instead of simply minimizing the noise as in the original LOCI algorithm. The TLOCI technique uses an input spectrum and template Point Spread Functions (PSFs, generated from unocculted and unsaturated stellar images) to optimize the reference image least-squares coefficients to minimize the planet self-subtraction, thus maximizing its throughput per wavelength, while simultaneously providing a maximum suppression of the speckle noise. The new algorithm has been developed using on-sky GPI data and has achieved impressive contrast. This paper presents the TLOCI algorithm, on-sky performance, and will discuss the challenges in recovering the planet spectrum with high fidelity.

arXiv comment13 pages, 8 figures, to appear in Proceedings of SPIE 9148

References in corpus (18)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Images of a fourth planet orbiting HR 8799
• Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
• Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages
• A probable giant planet imaged in the Beta Pictoris disk
• Direct Imaging and Spectroscopy of a Planetary Mass Candidate Companion to a Young Solar Analog
• The Gemini NICI Planet-Finding Campaign: The Frequency of Planets around Young Moving Group Stars
• The International Deep Planet Survey I. The frequency of wide-orbit massive planets around A-stars
• Imaging Polarimetric Observations of a New Circumstellar Disk System
• The Gemini NICI Planet-Finding Campaign: The Frequency of Giant Planets around Young B and A Stars
• Direct Imaging Confirmation and Characterization of a Dust-Enshrouded Candidate Exoplanet Orbiting Fomalhaut
• Discovery of a wide planetary-mass companion to the young M3 star GU Psc
• Direct imaging discovery of 12-14 Jupiter mass object orbiting a young binary system of very low-mass stars
• A Combined VLT and Gemini Study of the Atmosphere of the Directly-Imaged Planet, beta Pictoris b
• Imaging extrasolar planets by stellar halo suppression in separately-corrected color bands
• Application of a damped Locally Optimized Combination of Images method to the spectral characterization of faint companions using an Integral Field Spectrograph
• Effects of Quasi-Static Aberrations in Faint Companion Searches
• NICI: combining coronagraphy, ADI, and SDI

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