Evolutionary models for ultracool dwarfs

Research output: Contribution to journalJournal articleResearchpeer-review

  • Catarina Silva Fernandes
  • Valérie Van Grootel
  • Sébastian J. A. J. Salmon
  • Bernhard Aringer
  • Adam J. Burgasser
  • Richard Scuflaire
  • Pierre Brassard
  • Gilles Fontaine
Ultracool dwarfs (UCDs) have emerged as key targets for searches of transiting exoplanets. Precise estimates of the host parameters (including mass, age, and radius) are fundamental to constraining the physical properties of orbiting exoplanets. We have extended our evolutionary code Code Liégeois d'Evolution Stellaire to the UCD regime. We include relevant equations of state (EOSs) for H, He, as well as C and O elements to cover the temperature–density regime of UCD interiors. For various metallicities, we couple the interior models to two sets of model atmospheres as surface boundary conditions. We show that including C and O in the EOS has a significant effect close to the H-burning limit mass. The typical systematic error associated with uncertainties in input physics in evolutionary models is ~0.0005 M⊙. We test model results against observations for objects whose parameters have been determined from independent techniques. We are able to reproduce dynamical mass measurements of LSPM J1314+1320AB within 1σ with the condition of varying the metallicity (determined from calibrations) up to 2.5σ. For GJ 65AB, a 2σ agreement is obtained between individual masses from differential astrometry and those from evolutionary models. We provide tables of UCD models for various masses and metallicities that can be used as reference when estimating parameters for ultracool objects.
Original languageEnglish
Article number94
JournalAstrophysical Journal
Volume879
Issue number2
Number of pages9
ISSN0004-637X
DOIs
Publication statusPublished - 2019

Links

ID: 224021747