Authors

‪Flavien Kiefer, Institut d’Astrophysique de ParisFollow
Guillaume Hébrard, Institut d’Astrophysique de ParisFollow
Johannes Sahlmann, Space Telescope Science Institute
Sérgio G. Sousa, Universidade do Porto
Thierry Forveille, Université Grenoble AlpesFollow
Nuno Santos, Universidade do PortoFollow
Michel Mayor, Observatoire astronomique de l’Université de Genève
Magali Deleuil, Aix-Marseille UniversitéFollow
Paul Anthony Wilson, Institut d’Astrophysique de ParisFollow
Shweta Dalal, Institut d’Astrophysique de ParisFollow
R. F. Díaz, Universidad de Buenos AiresFollow
Gregory W. Henry, Tennessee State UniversityFollow
Janis Hagelberg, Institute for Particle Physics and Astrophysics
Melissa J. Hobson, Aix-Marseille UniversitéFollow
Olivier Demangeon, Universidade do PortoFollow
Vincent Bourrier, Observatoire Astronomique de l’Université de GenèveFollow
Xavier Delfosse, Université Grenoble AlpesFollow
Luc Arnold, Observatoire de Haute-ProvenceFollow
Nicola Astudillo-Defru, Universidad Católica de la Santísima ConcepciónFollow
Jean-Luc Beuzit, Aix-Marseille Université
Isabelle Boisse, Aix-Marseille UniversitéFollow
Xavier Bonfils, Université Grenoble AlpesFollow
Simon Borgniet, Sorbonne Université
François Bouchy, Observatoire astronomique de l’Université de GenèveFollow
B. Courcol, Observatoire astronomique de l’Université de Genève
David Ehrenreich, Observatoire Astronomique de l’Université de GenèveFollow
Nathan Hara, Observatoire astronomique de l’Université de GenèveFollow
Anne-Marie Lagrange, Université Grenoble Alpes
Christophe Lovis, Observatoire astronomique de l’Université de GenèveFollow
Guillaume Montagnier, Institut d’Astrophysique de Paris
C. Moutou, Aix-Marseille UniversitéFollow
Francesco Pepe, Observatoire astronomique de l’Université de GenèveFollow
C. Perrier, Université Grenoble Alpes
Javiera Rey, Carnegie Institution for Science
Alexandre Santerne, Aix-Marseille UniversitéFollow
Damien Ségransan, Observatoire astronomique de l’Université de GenèveFollow
Stephane Udry, Observatoire astronomique de l’Université de GenèveFollow
Alfred Vidal-Madjar, Institut d’Astrophysique de ParisFollow

Document Type

Article

Publication Date

11-5-2019

Abstract

Context. Brown dwarfs (BD) are substellar objects intermediate between planets and stars with masses of ~13–80 MJ. While isolated BDs are most likely produced by gravitational collapse in molecular clouds down to masses of a few MJ, a non-negligible fraction of low-mass companions might be formed through the planet-formation channel in protoplanetary discs. The upper mass limit of objects formed within discs is still observationally unknown, the main reason being the strong dearth of BD companions at orbital periods shorter than 10 yr, also known as the BD desert.

Aims. To address this question, we aim at determining the best statistics of companions within the 10–100 MJ mass regime and located closer than ~10 au to the primary star, while minimising observation and selection bias.

Methods. We made extensive use of the radial velocity (RV) surveys of northern hemisphere FGK stars within 60 pc of the Sun, performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We derived the Keplerian solutions of the RV variations of 54 sources. Public astrometric data of the HIPPARCOS and Gaia missions allowed us to constrain the masses of the companions for most sources. We introduce GASTON, a new method to derive inclination combining RVs and Keplerian and astrometric excess noise from Gaia DR1.

Results. We report the discovery of 12 new BD candidates. For five of them, additional astrometric data led to a revision of their mass in the M-dwarf regime. Among the seven remaining objects, four are confirmed BD companions, and three others are likely also in this mass regime. Moreover, we report the detection of 42 M-dwarfs within the range of 90 MJ–0.52 M. The resulting M sin i-P distribution of BD candidates shows a clear drop in the detection rate below 80-day orbital period. Above that limit, the BD desert appears rather wet, with a uniform distribution of the M sin i. We derive a minimum BD-detection frequency around Solar-like stars of 2.0 ± 0.5%.

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