The SPHERE infrared survey for exoplanets (SHINE)

III. The demographics of young giant exoplanets below 300 au with SPHERE^★

¹ Aix Marseille Univ., CNRS, CNES, LAM, Marseille, France
e-mail: arthur.vigan@lam.fr
² Center for Space and Habitability, University of Bern, 3012 Bern, Switzerland
³ INAF – Osservatorio Astronomico di Padova, Vicolo della Osservatorio 5, 35122 Padova, Italy
⁴ Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA
⁵ Institute for Particle Physics and Astrophysics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland
⁶ Institute for Astronomy, University of Edinburgh, EH9 3HJ, Edinburgh, UK
⁷ Scottish Universities Physics Alliance (SUPA), Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ, UK
⁸ Centre for Exoplanet Science, SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews KY16 9SS, UK
⁹ Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany
¹⁰ Lunar and Planetary Laboratory, University of Arizona 1629 E. University Blvd. Tucson, AZ 85721, USA
¹¹ Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany
¹² LESIA, Observatoire de Paris, Université PSL, Université de Paris, CNRS, Sorbonne Université, 5 place Jules Janssen, 92195 Meudon, France
¹³ Unidad Mixta Internacional Franco-Chilena de Astronomía, CNRS/INSU UMI 3386 and Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
¹⁴ STAR Institute, University of Liège, Allée du Six Août 19c, 4000 Liège, Belgium
¹⁵ Centre for Exoplanet Science, University of Edinburgh, Edinburgh EH9 3FD, UK
¹⁶ Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
¹⁷ Department of Astronomy, Stockholm University, 10691 Stockholm, Sweden
¹⁸ CRAL, CNRS, Université Lyon 1, Université de Lyon, ENS, 9 avenue Charles Andre, 69561 Saint Genis Laval, France
¹⁹ INAF – Catania Astrophysical Observatory, Via S. Sofia 78, 95123 Catania, Italy
²⁰ Univ. de Toulouse, CNRS, IRAP, 14 avenue Belin, 31400 Toulouse, France
²¹ ONERA (Office National dEtudes et de Recherches Arospatiales), BP 72, 92322 Chatillon, France
²² European Southern Observatory (ESO), Karl-Schwarzschild-Str. 2, 85748 Garching, Germany
²³ Geneva Observatory, University of Geneva, Chemin des Mailettes 51, 1290 Versoix, Switzerland
²⁴ Université Côte d’Azur, OCA, CNRS, Lagrange, France
²⁵ Anton Pannekoek Institute for Astronomy, Science Park 9, 1098 XH Amsterdam, The Netherlands
²⁶ Leiden Observatory, Leiden University, PO Box 9513, 2300 RA Leiden, The Netherlands
²⁷ INAF – Osservatorio Astronomico di Brera, Via E. Bianchi 46, 23807 Merate, Italy
²⁸ Núcleo de Astronomía, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
²⁹ Escuela de Ingeniería Industrial, Facultad de Ingeniería y Ciencias, Universidad Diego Portales, Av. Ejercito 441, Santiago, Chile
³⁰ INAF – Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Napoli, Italy
³¹ European Southern Observatory, Alonso de Còrdova 3107, Vitacura, Casilla 19001, Santiago, Chile
³² Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
³³ Instituto de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Av. Gran Bretaña 1111, Valparaíso, Chile
³⁴ Núcleo Milenio Formación Planetaria – NPF, Universidad de Valparaíso, Av. Gran Bretaña 1111, Valparaíso, Chile
³⁵ NOVA Optical Infrared Instrumentation Group, Dwingeloo, The Netherlands

Received: 7 April 2020
Accepted: 4 July 2020

Abstract

The SpHere INfrared Exoplanet (SHINE) project is a 500-star survey performed with SPHERE on the Very Large Telescope for the purpose of directly detecting new substellar companions and understanding their formation and early evolution. Here we present an initial statistical analysis for a subsample of 150 stars spanning spectral types from B to M that are representative of the full SHINE sample. Our goal is to constrain the frequency of substellar companions with masses between 1 and 75 M_Jup and semimajor axes between 5 and 300 au. For this purpose, we adopt detection limits as a function of angular separation from the survey data for all stars converted into mass and projected orbital separation using the BEX-COND-hot evolutionary tracks and known distance to each system. Based on the results obtained for each star and on the 13 detections in the sample, we use a Markov chain Monte Carlo tool to compare our observations to two different types of models. The first is a parametric model based on observational constraints, and the second type are numerical models that combine advanced core accretion and gravitational instability planet population synthesis. Using the parametric model, we show that the frequencies of systems with at least one substellar companion are 23.0_−9.7^+13.5, 5.8_−2.8^+4.7, and 12.6_−7.1^+12.9% for BA, FGK, and M stars, respectively. We also demonstrate that a planet-like formation pathway probably dominates the mass range from 1–75 M_Jup for companions around BA stars, while for M dwarfs, brown dwarf binaries dominate detections. In contrast, a combination of binary star-like and planet-like formation is required to best fit the observations for FGK stars. Using our population model and restricting our sample to FGK stars, we derive a frequency of 5.7_−2.8^+3.8%, consistent with predictions from the parametric model. More generally, the frequency values that we derive are in excellent agreement with values obtained in previous studies.