Browsing Research publications by Author "Lodieu, N."

Now showing items 21-33 of 33

    • Parallaxes and physical properties of 11 mid-to-late T dwarfs 

      Marocco, F.; Smart, R.L.; Jones, H.R.A.; Burningham, B.; Lattanzi, M.G.; Leggett, S.K.; Lucas, P.W.; Tinney, C.G.; Adamson, A.; Evans, D. W.; Lodieu, N.; Murray, D.N.; Pinfield, D.J.; Tamura, M. (2010)
      Aims. We present parallaxes of 11 mid-to-late T dwarfs observed in the UKIRT Infrared Deep Sky Survey. We use these results to test the reliability of model predictions in magnitude–color space, determine a magnitude-spectral ...

    • The physical properties of four ~600 K T dwarfs 

      Leggett, S.K.; Cushing, M.C.; Saumon, D.; Marley, M.; Roellig, T.L.; Warren, S.J.; Burningham, B.; Jones, H.R.A.; Kirkpatrick, J.D.; Lodieu, N.; Lucas, P.W.; Mainzer, A.K.; Martin, E.L.; McCaughrean, M.J.; Pinfield, D.J.; Sloan, G.C.; Smart, R.L.; Tamura, M.; Van Cleve, J. (2009)
      We present Spitzer 7.6-14.5 μm spectra of ULAS J003402.77–005206.7 and ULAS J133553.45+113005.2, two T9 dwarfs with the latest spectral types currently known. We fit synthetic spectra and photometry to the near- through ...

    • 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 ...

    • Primeval very low-mass stars and brown dwarfs -- II. The most metal-poor substellar object 

      Zhang, Z. H.; Homeier, D.; Pinfield, David; Lodieu, N.; Jones, Hugh; Allard, F.; Pavlenko, Ya V. (2017-06-01)
      SDSS J010448.46+153501.8 has previously been classified as an sdM9.5 subdwarf. However, it's very blue J-K colour (-0.15+/-0.17) suggests a much lower metallicity compared to normal sdM9.5 subdwarfs. Here we re-classify ...

    • Primeval very low-mass stars and brown dwarfs -- VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf 

      Zhang, Z. H.; Raddi, R.; Burgasser, A. J.; Casewell, S. L.; Smart, R. L.; Galvez-Ortiz, M. C.; Jones, H. R. A.; Baig, S.; Lodieu, N.; Gauza, B.; Pavlenko, Ya V.; Jiao, Y. F.; Zhao, Z. K.; Zhou, S. Y.; Pinfield, D. J. (2024-09-01)
      We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV ...

    • 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 ...

    • Properties of the Coolest Dwarfs 

      Leggett, S.K.; Freedman, R.; Geballe, T.; Golimowski, D.; Lodieu, N.; Marley, M.; Pinfield, D.J.; Saumon, D.; Stephens, D.; Warren, S.J. (Astronomical Society of the Pacific, 2008)
      Eleven years after the discovery of the first T dwarf, a population of ultracool L and T dwarfs has been identified that is large enough to show a range of atmospheric properties. Also, model atmospheres are sufficiently ...

    • The UKIRT Infrared Deep Sky Survey (UKIDSS) 

      Lawrence, A.; Warren, S. J.; Almaini, O.; Edge, A. C.; Hambly, N. C.; Jameson, R. F.; Casali, M.; Adamson, A.; Dye, S.; Emerson, J. P.; Foucaud, S.; Hewett, P.; Hirst, P.; Hodgkin, S. T.; Irwin, M. J.; Lodieu, N.; McMahon, R. G.; Simpson, C.; Smail, I.; Mortlock, D.; Folger, M.; Lucas, P.W. (2006-04-20)
      We describe the goals, design, implementation, and initial progress of the UKIRT Infrared Deep Sky Survey (UKIDSS), a seven year sky survey which began in May 2005, using the UKIRT Wide Field Camera. It is a portfolio of ...

    • A very cool brown dwarf in UKIDSS DR1 

      Warren, S.J.; Mortlock, D.J.; Leggett, S.K.; Pinfield, D.J.; Homeier, D.; Dye, S.; Jameson, R.F.; Lodieu, N.; Lucas, P.W.; Adamson, A.J.; Allard, F.; Barrado y Navascues, D.; Casali, M.; Chiu, K.; Hambly, N.C.; Hewett, P.C.; Hirst, P.; Irwin, M.J.; Lawrence, A.; Liu, M.C.; Martin, E.L.; Smart, R.L.; Valdivielso, L.; Venemans, B.P. (2007)

    • Very low-luminosity Class I/flat outflow sources in sigma Orionis 

      Riaz, Basmah; Thompson, M.A.; Whelan, E.T.; Lodieu, N. (2015-01-21)
      We present an optical to submillimetre multiwavelength study of two very low-luminosity Class I/flat systems, Mayrit 1701117 and Mayrit 1082188, in the σ Orionis cluster. We performed moderate-resolution (R ∼ 1000) optical ...

    • A wide deep infrared look at the Pleiades with UKIDSS : New constraints on the substellar binary fraction and the low-mass initial mass function 

      Lodieu, N.; Dobbie, P. D.; Deacon, N. R.; Hodgkin, S. T.; Hambly, N. C.; Jameson, R. F. (2007-09-01)
      We present the results of a deep wide-field near-infrared survey of 12 deg2 of the Pleiades conducted as part of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey (GCS). ...