instrumentation: high angular resolution; methods: observational; techniques: image processing; planets and satellites: detection; Astrophysics - Instrumentation and Methods for Astrophysics; Astrophysics - Earth and Planetary Astrophysics
Abstract :
[en] Context. The consortium of the Spectro-Polarimetric High-contrast Exoplanet REsearch installed at the Very Large Telescope (SPHERE/VLT) has been operating its guaranteed observation time (260 nights over five years) since February 2015. The main part of this time (200 nights) is dedicated to the detection and characterization of young and giant exoplanets on wide orbits. <BR /> Aims: The large amount of data must be uniformly processed so that accurate and homogeneous measurements of photometry and astrometry can be obtained for any source in the field. <BR /> Methods: To complement the European Southern Observatory pipeline, the SPHERE consortium developed a dedicated piece of software to process the data. First, the software corrects for instrumental artifacts. Then, it uses the speckle calibration tool (SpeCal) to minimize the stellar light halo that prevents us from detecting faint sources like exoplanets or circumstellar disks. SpeCal is meant to extract the astrometry and photometry of detected point-like sources (exoplanets, brown dwarfs, or background sources). SpeCal was intensively tested to ensure the consistency of all reduced images (cADI, Loci, TLoci, PCA, and others) for any SPHERE observing strategy (ADI, SDI, ASDI as well as the accuracy of the astrometry and photometry of detected point-like sources. <BR /> Results: SpeCal is robust, user friendly, and efficient at detecting and characterizing point-like sources in high contrast images. It is used to process all SPHERE data systematically, and its outputs have been used for most of the SPHERE consortium papers to date. SpeCal is also a useful framework to compare different algorithms using various sets of data (different observing modes and conditions). Finally, our tests show that the extracted astrometry and photometry are accurate and not biased. <P />Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programme 097.C-0865.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Galicher, R.; Lesia, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, Univ. Paris Diderot, UPMC Univ. Paris 06, Sorbonne Paris Cité, 5 place Jules Janssen, 92190, Meudon, France
Boccaletti, A.; Lesia, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, Univ. Paris Diderot, UPMC Univ. Paris 06, Sorbonne Paris Cité, 5 place Jules Janssen, 92190, Meudon, France
Mesa, D.; INAF - Osservatorio Astronomico di Padova, Vicolo della Osservatorio 5, 35122, Padova, Italy ; INCT, Universidad De Atacama, calle Copayapu 485, Copiapó, Atacama, Chile
Delorme, P.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Gratton, R.; INAF - Osservatorio Astronomico di Padova, Vicolo della Osservatorio 5, 35122, Padova, Italy
Langlois, M.; Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France ; CRAL, UMR 5574, CNRS, Université de Lyon, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69364, Lyon Cedex 07, France
Lagrange, A.-M.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Le Coroller, H.; Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France
Chauvin, G.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Biller, B.; Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
Cantalloube, F.; Max-Planck-Institut für Astronomie, Königstuhl 17, 69117, Heidelberg, Germany
Janson, M.; Department of Astronomy, Stockholm University, 106 91, Stockholm, Sweden
Lagadec, E.; Université Côte d'Azur, OCA, CNRS, Lagrange, France
Meunier, N.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Vigan, A.; Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France
Hagelberg, J.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Bonnefoy, M.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Zurlo, A.; Universidad de Chile, Camino el Observatorio 1515, Santiago, Chile ; Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile ; Millenium Nucleus "Protoplanetary Disks in ALMA Early Science", Valparaiso, Chile
Rocha, S.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Maurel, D.; Université Grenoble Alpes, CNRS, IPAG, 38000, Grenoble, France
Jaquet, M.; Aix-Marseille Université, CNRS, LAM (Laboratoire d'Astrophysique de Marseille) UMR 7326, 13388, Marseille, France
Buey, T.; Lesia, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, Univ. Paris Diderot, UPMC Univ. Paris 06, Sorbonne Paris Cité, 5 place Jules Janssen, 92190, Meudon, France
Weber, L.; Lesia, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, Univ. Paris Diderot, UPMC Univ. Paris 06, Sorbonne Paris Cité, 5 place Jules Janssen, 92190, Meudon, France ; Geneva Observatory, University of Geneva, Chemin des Mailettes 51, 1290, Versoix, Switzerland)