Now showing items 1-4 of 4

    • Primeval very low-mass stars and brown dwarfs - III. The halo transitional brown dwarfs 

      Zhang, Z. H.; Pinfield, D. J.; Galvez-Ortiz, M. C.; Homeier, D.; Burgasser, A. J.; Lodieu, N.; Martin, E. L.; Osorio, M. R. Zapatero; Allard, F.; Jones, H. R. A.; Smart, R. L.; Marti, B. Lopez; Burningham, B.; Rebolo, R. (2018-09-01)
      We report the discovery of an esdL3 subdwarf, ULAS J020858.62+020657.0 and a usdL4.5 subdwarf, ULAS J230711.01+014447.1. They were identified as L subdwarfs by optical spectra obtained with the Gran Telescopio Canarias, ...
    • Primeval very low-mass stars and brown dwarfs - IV. New L subdwarfs, Gaia astrometry, population properties, and a blue brown dwarf binary 

      Zhang, Z. H.; Galvez-Ortiz, M. C.; Pinfield, D. J.; Burgasser, A. J.; Lodieu, N.; Jones, H. R. A.; Martin, E. L.; Burningham, B.; Homeier, D.; Allard, F.; Osorio, M. R. Zapatero; Smith, L. C.; Smart, R. L.; Marti, B. Lopez; Marocco, F.; Rebolo, R. (2018-11-11)
      We present 27 new L subdwarfs and classify five of them as esdL and 22 as sdL. Our L subdwarf candidates were selected with the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Spectroscopic follow-up was carried ...
    • Primeval very low-mass stars and brown dwarfs - VI. Population properties of metal-poor degenerate brown dwarfs 

      Zhang, Z. H.; Burgasser, A. J.; Galvez-Ortiz, M. C.; Lodieu, N.; Osorio, M. R. Zapatero; Pinfield, D. J.; Allard, F. (2019-06-01)
      We presented 15 new T dwarfs that were selected from UKIRT Infrared Deep Sky Survey, Visible and Infrared Survey Telescope for Astronomy, and Wide-field Infrared Survey Explorer surveys, and confirmed with optical to near ...
    • Ultracool dwarf benchmarks with \emph{Gaia} primaries 

      Marocco, F.; Pinfield, D. J.; Cook, N. J.; Osorio, M. R. Zapatero; Montes, D.; Caballero, J. A.; Gálvez-Ortiz, M. C.; Gromadzki, M.; Jones, H. R. A.; Kurtev, R.; Smart, R. L.; Zhang, Z.; Lavers, A. L. Cabrera; Álvarez, D. García; Qi, Z. X.; Rickard, M. J.; Dover, L. (2017-10-01)
      We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool ...