Improving Signal to Noise in the Direct Imaging of Exoplanets and Circumstellar Disks

  title={Improving Signal to Noise in the Direct Imaging of Exoplanets and Circumstellar Disks},
  author={Z. Wahhaj and Lucas A. Cieza and Dimitri Mawet and Bin Yang and Hector C{\'a}novas and Jos de Boer and Simon Casassus and François M{\'e}nard and Matthias R. Schreiber and Michael C. Liu and Beth A. Biller and Eric L. Nielsen and Thomas L. Hayward},
  journal={arXiv: Earth and Planetary Astrophysics},
We present a new algorithm designed to improve the signal to noise ratio (SNR) of point and extended source detections in direct imaging data. The novel part of our method is that it nds the linear combination of the science images that best match counterpart images with signal removed from suspected source regions. The algorithm, based on the Locally Optimized Combination of Images (LOCI) method, is called Matched LOCI or MLOCI. We show using data obtained with the Gemini Planet Imager (GPI… 
Exoplanet detection in angular and spectral differential imaging: local learning of background correlations for improved detections
The principle of the PACO algorithm is recalled and new illustrations of its benefits in terms of detection capabilities on datasets from the VLT/SPHERE-IRDIS instrument are given and the performance of PACO is compared to state-of-the-art algorithms such as TLOCI and KLIP-PCA.
PACO ASDI: an algorithm for exoplanet detection and characterization in direct imaging with integral field spectrographs
Context.Exoplanet detection and characterization by direct imaging both rely on sophisticated instruments (adaptive optics and coronagraph) and adequate data processing methods. Angular and spectral
An Unsupervised Patch-Based Approach for Exoplanet Detection by Direct Imaging
This work explicitly model the spatial correlations of the background and design a completely unsupervised method that accounts for the background non-stationarity in exoplanet detection on datasets obtained with SPHERE instrument operating at the Very Large Telescope in Chile.
Detection and Characterization of Exoplanets using Projections on Karhunen Loeve Eigenimages: Forward Modeling
This paper considers the case of the spectral extraction of faint point sources in IFS data and illustrates, using public Gemini Planet Imager commissioning data, that the novel perturbation-based Karhunen-Lo\`eve Image Processing Forward Modeling (KLIP-FM) can indeed alleviate algorithmic biases.
Detection and characterization of exoplanets in high contrast images by the inverse problem approach
Direct imaging of exoplanets provides valuable information about the light they emit, their interactions with their host star environment and their nature. In order to image such objects, advanced
Exoplanet detection in angular differential imaging by statistical learning of the nonstationary patch covariances
Context. The detection of exoplanets by direct imaging is an active research topic in astronomy. Even with the coupling of an extreme adaptive-optics system with a coronagraph, it remains challenging
The Faintest WISE Debris Disks: Enhanced Methods for Detection and Verification
In an earlier study, we reported nearly 100 previously unknown dusty debris disks around Hipparcos main-sequence stars within 75 pc by selecting stars with excesses in individual WISE colors. Here,
Spectral and angular differential imaging with SPHERE/IFS
Context. Direct imaging of exoplanets is a challenging task that requires state-of-the-art instrumentation and advanced imageprocessing techniques. Differential imaging techniques have proven useful
Spectral and atmospheric characterization of 51 Eridani b using VLT/SPHERE
Context. 51 Eridani b is an exoplanet around a young (20 Myr) nearby (29.4 pc) F0-type star, which was recently discovered by direct imaging. It is one of the closest direct imaging planets in
Global optimization-based reference star differential imaging for high-contrast exoplanet imaging survey
  • D. Ren, Yili Chen
  • Physics, Geology
    Monthly Notices of the Royal Astronomical Society
  • 2021
We propose a data reduction approach called global optimization-based reference star differential imaging (G-RDI), which can be used for exoplanet imaging survey, where large numbers of target


Detection and Characterization of Exoplanets and Disks using Projections on Karhunen-Loeve Eigenimages
We describe a new method to achieve point spread function (PSF) subtractions for high- contrast imaging using Principal Component Analysis (PCA) that is applicable to both point sources or extended
GPI PSF subtraction with TLOCI: the next evolution in exoplanet/disk high-contrast imaging
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, and has achieved impressive contrast.
The Gemini NICI Planet-Finding Campaign: The Companion Detection Pipeline
We present the high-contrast image processing techniques used by the Gemini NICI Planet-Finding Campaign to detect faint companions to bright stars. NICI (Near Infrared Coronagraphic Imager) is an
Application of a Damped Locally Optimized Combination of Images Method to the Spectral Characterization of Faint Companions Using an Integral Field Spectrograph
High-contrast imaging instruments are now being equipped with integral field spectrographs (IFSs) to facilitate the detection and characterization of faint substellar companions. Algorithms currently
PYNPOINT: An image processing package for finding exoplanets
PynPoint, the Python-based software package that uses principle component analysis to detect and estimate the exoplanets in two dimensional imaging data, shows that the performance of this approach gives a marked improvement over what is presently possible using existing methods such as LOCI.
Direct imaging of exoplanets is limited by bright quasi-sta tic speckles in the point spread function (PSF) of the central star. This limitation can be reduced by subtract ion of reference PSF
Imaging Spectroscopy for Extrasolar Planet Detection
We propose that coronagraphic imaging in combination with moderate to high spectral resolution from the outset may prove more effective in both detecting extrasolar planets and characterizing them
Polarimetry with the gemini planet imager: Methods, performance at first light, and the circumstellar ring around HR 4796A
We present the first results from the polarimetry mode of the Gemini Planet Imager (GPI), which uses a new integral field polarimetry architecture to provide high contrast linear polarimetry with
Very high contrast integral field spectroscopy of AB Doradus C: 9-mag contrast at 0.2 arcsec without a coronagraph using spectral deconvolution
We present an extension of the spectral deconvolution (SD) method to achieve very high contrast at small inner working radii. We apply the method to the specific case of ground-based adaptive optics
Experimental Design for the Gemini Planet Imager
The Gemini Planet Imager (GPI) is a high-performance adaptive optics system being designed and built for the Gemini Observatory. GPI is optimized for high-contrast imaging, combining precise and