VIP : Vortex Image Processing Package for High-contrast Direct Imaging

Carlos Alberto Gomez Gonzalez (1) , Olivier Wertz (1) , Olivier Absil (1) , Valentin Christiaens (1, 2, 3) , Denis Defrère (1) , Dimitri Mawet (4, 5) , Julien Milli (6) , Pierre-Antoine Absil (7) , Marc Van Droogenbroeck (8) , Faustine Cantalloube (9, 10) , Philip M. Hinz (11) , Andrew J. Skemer (12) , Mikael Karlsson (13) , Jean Surdej (1)

1 STAR - Space Sciences, Technologies and Astrophysics Research Institute
2 USACH - Universidad de Santiago de Chile [Santiago]
3 Millennium Nucleus Protoplanetary Disk
4 CALTECH - California Institute of Technology
5 JPL - Jet Propulsion Laboratory
6 ESO - European Southern Observatory [Santiago]
7 UCL - Université Catholique de Louvain = Catholic University of Louvain
8 Institut Montefiore - Département d'Electricité, Electronique et Informatique (Liège)
9 IPAG - Institut de Planétologie et d'Astrophysique de Grenoble
10 DOTA, ONERA, Université Paris Saclay (COmUE) [Palaiseau]
11 Steward Observatory
12 UC Santa Cruz - University of California [Santa Cruz]
13 Angström Laboratory

We present the Vortex Image Processing (VIP) library, a python package dedicated to astronomical high-contrast imaging. Our package relies on the extensive python stack of scientific libraries and aims to provide a flexible framework for high-contrast data and image processing. In this paper, we describe the capabilities of VIP related to processing image sequences acquired using the angular differential imaging (ADI) observing technique. VIP implements functionalities for building high-contrast data processing pipelines, encompassing pre- and post-processing algorithms, potential source position and flux estimation, and sensitivity curve generation. Among the reference point-spread function subtraction techniques for ADI post-processing, VIP includes several flavors of principal component analysis (PCA) based algorithms, such as annular PCA and incremental PCA algorithms capable of processing big datacubes (of several gigabytes) on a computer with limited memory. Also, we present a novel ADI algorithm based on non-negative matrix factorization, which comes from the same family of low-rank matrix approximations as PCA and provides fairly similar results. We showcase the ADI capabilities of the VIP library using a deep sequence on HR 8799 taken with the LBTI/LMIRCam and its recently commissioned L-band vortex coronagraph. Using VIP, we investigated the presence of additional companions around HR 8799 and did not find any significant additional point source beyond the four known planets. VIP is available at http://github.com/vortex-exoplanet/VIP and is accompanied with Jupyter notebook tutorials illustrating the main functionalities of the library.

Mots clés: METHODS; DATA ANALYSIS; PLANETARY SYSTEMS; PLANETS AND SATELLITES: DETECTION; TECHNIQUES: HIGH ANGULAR RESOLUTION; TECHNIQUES: IMAGE PROCESSING

Mots clés: ANALYSE DONNEES; SYSTEME PLANETAIRE; DETECTION PLANETE; HAUTE RESOLUTION ANGULAIRE; TRAITEMENT IMAGE

Domaines: Optique / photonique

Carlos Alberto Gomez Gonzalez, Olivier Wertz, Olivier Absil, Valentin Christiaens, Denis Defrère, et al.. VIP : Vortex Image Processing Package for High-contrast Direct Imaging. The Astronomical Journal, 2017, 154 (1-14), ⟨10.3847/1538-3881/aa73d7⟩. ⟨hal-01852210⟩