Now showing items 1-11 of 11

    • 76 T dwarfs from the UKIDSS LAS : benchmarks, kinematics and an updated space density 

      Burningham, B.; Cardoso, C. V.; Smith, Leigh; Leggett, S.K.; Smart, R.L.; Mann, A. W.; Dhital, S.; Lucas, P.W.; Tinney, C.G.; Pinfield, D.J.; Zhang, Z.; Morley, C.; Saumon, D.; Aller, K.; Littlefair, S. P.; Homeier, D.; Lodieu, N.; Deacon, Niall; Marley, M. S.; van Spaandonk, L.; Baker, D.; Allard, F.; Andrei, A.H.; Canty, J.; Clarke, J.; Day-Jones, A. C.; Dupuy, T.; Fortney, J. J.; Gomes, J.; Ishii, M.; Jones, H.R.A.; Liu, M.; Magazzu, A.; Marocco, F.; Murray, D. N.; Rojas-Ayala, B.; Tamura, M. (2013-07)
      We report the discovery of 76 new T dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). Near-infrared broad- and narrow-band photometry and spectroscopy are presented for the new objects, along ...
    • The brightest pure-H ultracool white dwarf 

      Catalan, S.; Tremblay, P. -E.; Pinfield, D.J.; Smith, Leigh; Zhang, Z. H.; Napiwotzki, R.; Marocco, F.; Day-Jones, A. C.; Gomes, J.; Forde, K.P.; Lucas, P.W.; Jones, H.R.A. (2012-10)
      We report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo ...
    • A deep WISE search for very late type objects and the discovery of two halo/thick-disc T dwarfs : WISE 0013+0634 and WISE 0833+0052 

      Pinfield, D.J.; Gomes, J.; Day-Jones, A. C.; Leggett, S.K.; Gromadzki, M.; Burningham, B.; Ruiz, M. T.; Kurtev, R.; Cattermole, T.; Cardoso, C.; Lodieu, N.; Faherty, J.; Littlefair, S.; Smart, R.; Irwin, M.; Clarke, J. R. A.; Smith, Leigh; Lucas, P.W.; Galvez-Ortiz, M. C.; Jenkins, J. S.; Jones, H.R.A.; Rebolo, R.; Bejar, V. J. S.; Gauza, B. (2014-01-11)
      A method is defined for identifying late-T and Y dwarfs in WISE down to low values of signal-to-noise. This requires a WISE detection only in the W2-band and uses the statistical properties of the WISE multiframe measurements ...
    • Discovery of a new Y dwarf: WISE J030449.03-270508.3 

      Pinfield, D.J.; Gromadzki, M.; Leggett, S.K.; Gomes, J.; Lodieu, N.; Kurtev, R.; Day-Jones, A. C.; Ruiz, M. T.; Cook, N. J.; Morley, C.V.; Marley, M. S.; Marocco, F.; Smart, R.L.; Jones, H.R.A.; Lucas, P.W.; Beletsky, Y.; Ivanov, V. D.; Burningham, B.; Jenkins, J. S.; Cardoso, C.; Frith, J.; Clarke, J. R. A.; Gálvez-Ortiz, M. C.; Zhang, Z. (2014-10-21)
      We present a new Y dwarf, WISE J030449.03−270508.3, confirmed from a candidate sample designed to pick out low-temperature objects from the Wide-field Infrared Survey Explorer (WISE) data base. The new object is typed Y0pec ...
    • Discovery of the benchmark metal poor T8 dwarf BD+01 2920B 

      Pinfield, D.J.; Burningham, B.; Lodieu, N.; Leggett, S.; Tinney, C.G.; van Spaandonk, L.; Marocco, F.; Smart, R.; Gomes, J.; Smith, Leigh; Lucas, P.W.; Day-jones, A.; Murray, D.; Katsiyannis, A. C.; Catalan, S.; Cardoso, C.; Clarke, James; Folkes, S.; Galvez-Ortiz, M.; Homeier, D.; Jenkins, J.; Jones, H.R.A.; Zhang, Z. (2012)
      We have searched the Wide-field Infrared Survey Explorer first data release for widely separated (<=10,000AU) late T dwarf companions to Hipparcos and Gliese stars. We have discovered a new binary system containing a K-band ...
    • The discovery of the T8.5 dwarf UGPS J0521+3640 

      Burningham, B.; Lucas, P.W.; Leggett, S.K.; Smart, R.; Baker, D.; Pinfield, D.J.; Tinney, C. G.; Homeier, D.; Allard, F.; Zhang, Z. H.; Gomes, J.; Day-Jones, A. C.; Jones, H.R.A.; Kovacs, G.; Lodieu, N.; Marocco, F.; Murray, D. N.; Sipocz, B. (2011-06)
      We have carried out a search for late-type T dwarfs in the UKIRT Infrared Deep Sky Survey Galactic Plane Survey 6th Data Release. The search yielded two persuasive candidates, both of which have been confirmed as T dwarfs. ...
    • Primeval very low-mass stars and brown dwarfs. I. Six new L subdwarfs, classification and atmospheric properties 

      Zhang, Z. H.; Pinfield, D. J.; Galvez-Ortiz, M. C.; Burningham, B.; Lodieu, N.; Marocco, F.; Burgasser, A. J.; Day-Jones, A. C.; Allard, F.; Jones, H. R. A.; Homeier, D.; Gomes, J.; Smart, R. L. (2017-01-01)
      We have conducted a search for L subdwarf candidates within the photometric catalogues of the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Six of our candidates are confirmed as L subdwarfs spectroscopically ...
    • The properties of the T8.5p dwarf Ross 458C 

      Burningham, B.; Leggett, S.K.; Homeier, D.; Saumon, D.; Lucas, P.W.; Pinfield, D.J.; Tinney, C. G.; Allard, F.; Marley, M. S.; Jones, H.R.A.; Murray, D. N.; Ishii, M.; Day-Jones, A.; Gomes, J.; Zhang, Z. H. (2011-07)
      We present near-infrared photometry and spectroscopy, and warm-Spitzer IRAC photometry of the young very cool T dwarf Ross 458C, which we have typed as T8.5p. By applying the fiducial age constraints (<= 1 Gyr) imposed by ...
    • Purple dwarfs : New L subdwarfs from UKIDSS and SDSS 

      Zhang, Z. H.; Pinfield, D.J.; Burningham, B.; Jones, H.R.A.; Day-Jones, A. C.; Marocco, F.; Gomes, J.; Galvez-Ortiz, M. C. (EDP Sciences, 2013)
      The first L subdwarf was a discovered only ten years ago. Less than ten L subdwarfs been published in the literature to date. Metal-poor ultracool atmospheres has not been well understood. Halo mass function cross substellar ...
    • A spectroscopic and proper motion search of Sloan Digital Sky Survey : red subdwarfs in binary systems 

      Zhang, Z. H.; Pinfield, D.J.; Burningham, B.; Jones, H.R.A.; Galvez-Ortiz, M. C.; Catalan, S.; Smart, R. L.; Lepine, S.; Clarke, J. R. A.; Pavlenko, Ya V.; Murray, D. N.; Kuznetsov, M. K.; Day-Jones, A. C.; Gomes, J.; Marocco, F.; Sipocz, B. (2013-09)
      Red subdwarfs in binary systems are crucial for both model calibration and spectral classification. We search for red subdwarfs in binary systems from a sample of high proper motion objects with Sloan Digital Sky Survey ...
    • The sub-stellar birth rate from UKIDSS 

      Day-Jones, A. C.; Marocco, F.; Pinfield, D.J.; Zhang, Z. H.; Burningham, B.; Deacon, Niall; Ruiz, M. T.; Gallardo, J.; Jones, H.R.A.; Lucas, P.W.; Jenkins, J. S.; Gomes, J.; Folkes, S. L.; Clarke, J. R. A. (2013-04)
      We present a new sample of mid-L to mid-T dwarfs with effective temperatures of 11001700 K selected from the UKIDSS Large Area Survey (LAS) and confirmed with infrared spectra from X-shooter/Very Large Telescope. This ...