Browsing University of Hertfordshire by Author "Tamura, M."

Now showing items 1-20 of 57

    • 47 new T dwarfs from the UKIDDS large area survey 

      Burningham, B.; Pinfield, D.J.; Lucas, P.W.; Leggett, S.K.; Deacon, Niall; Tamura, M.; Tinney, C.G.; Lodieu, N.; Zhang, Z.; Huelamo, N.; Jones, H.R.A.; Murray, D.N.; Mortlock, D.J.; Patel, M.; Barrado y Navascues, D.; Zapatero Osorio, M.R.; Ishii, M.; Kuzuhara, M.; Smart, R.L. (2010)
      We report the discovery of 47 new T dwarfs in the Fourth Data Release (DR4) from the Large Area Survey (LAS) of the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey with spectral types ranging from T0 to ...

    • 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 ...

    • Blue not brown: UKIRT Infrared Deep Sky Survey T dwarfs with suppressed K-band flux 

      Murray, D. N.; Burningham, B.; Jones, H.R.A.; Pinfield, D.J.; Lucas, P.W.; Leggett, S. K.; Tinney, C. G.; Day-Jones, A. C.; Weights, D. J.; Lodieu, N.; Perez Prieto, J. A.; Nickson, E.; Zhang, Z. H.; Clarke, J. R. A.; Jenkins, J. S.; Tamura, M. (2011-06)
      We have used blue near-infrared colours to select a group of 12 spectroscopically confirmed United Kingdom InfraRed Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) T dwarfs later than T4. From amongst these, we identify ...

    • Circular polarisation in star-forming regions : possible implications for homochirality 

      Hough, J.; Bailey, J.; Chrysostomou, A.; Gledhill, T.; Lucas, P.W.; Tamura, M.; Clark, S.; Yates, J.A.; Menard, F. (2001)

    • Circular Polarization in Star- Formation Regions : Implications for Biomolecular Homochirality 

      Bailey, J.; Chrysostomou, A.; Hough, J.; Gledhill, T.; McCall, A.; Clark, S.; Menard, F.; Tamura, M. (1998)
      Strong infrared circular polarization resulting from dust scattering in reflection nebulae in the Orion OMC-1 star-formation region has been observed. Circular polarization at shorter wavelengths might have been important ...

    • A circumstellar disk associated with a massive protostellar object 

      Jiang, Z.; Tamura, M.; Fukagawa, M.; Hough, J.; Lucas, P.W.; Suto, H.; Ishii, M.; Yang, J. (2005)

    • A deep survey of Brown Dwarfs in Orion with Gemini 

      Lucas, P.W.; Roche, P.F.; Tamura, M. (2005)

    • Detection of a warm molecular wind in DG Tauri 

      Takami, M.; Chrysostomou, A.; Ray, T.P.; Davis, C.J.; Dent, W.R.; Bailey, J.; Tamura, M.; Terada, H. (2004-03)

    • The discovery of a very cool binary system 

      Burningham, B.; Leggett, S.K.; Lucas, P.W.; Pinfield, D.J.; Smart, R.L.; Day-Jones, A.C.; Jones, H.R.A.; Murray, D.N.; Nickson, E.; Tamura, M.; Zhang, Z.; Lodieu, N.; Tinney, C.G.; Zapatero Osorio, M.R. (2010)
      We report the discovery of a very cool d/sdL7+T7.5p common proper motion binary system, SDSS J1416+13AB, found by cross-matching the United Kingdom Infrared Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Large Area ...

    • The discovery of an M4+T8.5 binary system 

      Burningham, B.; Pinfield, D.J.; Leggett, S.K.; Tinney, C.G.; Liu, M.C.; Homeier, D.; West, A.A.; Day-Jones, A.C.; Huelamo, N.; Dupuy, T.J.; Zhang, Z.; Murray, D.N.; Lodieu, N.; Navascues, D.B.Y.; Folkes, S.; Galvez-Ortiz, M.C.; Jones, H.R.A.; Lucas, P.W.; Calderon, M.M.; Tamura, M. (2009)
      We report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. [Please see original online abstract for complete version with correct notation]

    • The effect of airborne dust on astronomical polarization measurements 

      Bailey, Jeremy; Ulanowski, Z.; Lucas, P.W.; Hough, J. H.; Hirst, E.; Tamura, M. (2008-05-11)
      In the past, it has generally been assumed that polarization observations made with ground-based telescopes are unaffected by the passage of light through the Earth's atmosphere. Here, we report observations with a new ...

    • Extended High Circular Polarization in the Orion Massive Star Forming Region: Implications for the Origin of Homochirality in the Solar System 

      Fukue, T.; Tamura, M.; Kandori, R.; Kusakabe, N.; Hough, J.; Bailey, J.; Whittet, D.C.B.; Lucas, P.W.; Nakajima, Y.; Hashimoto, J. (2010)
      We present a wide-field (∼6′ × 6′) and deep near-infrared (K s band: 2.14 μm) circular polarization image in the Orion nebula, where massive stars and many low-mass stars are forming. Our results reveal that a high circular ...

    • Fifteen new T dwarfs discovered in the UKIDSS Large Area Survey 

      Pinfield, D.J.; Burningham, B.; Tamura, M.; Leggett, S.K.; Lodieu, N.; Lucas, P.W.; Mortlock, D.J.; Warren, S.J.; Homeier, D.; Ishi, M.; Deacon, Niall; McMahon, R.G.; Hewett, P.C.; Zapatero Osorio, M.R.; Martin, E.L.; Jones, H.R.A.; Venemans, B.P.; Day-Jones, A.C.; Dobbie, P.D.; Folkes, S.; Dye, S.; Allard, F.; Baraffe, I.; Barrado y Navascues, D.; Casewell, S.L.; Chiu, K.; Chabrier, G.; Clarke, F.; Hodgkin, S.T.; Magazzu, A.; McCaughrean, M.J.; Moraux, E.; Nakajima, T.; Pavlenko, Y.; Tinney, C.G. (2008)
      We present the discovery of fifteen new T2.5-T7.5 dwarfs (with estimated distances between 24–93pc), identified in the first three main data releases of the UKIRT Infrared Deep Sky Survey. This brings the total number of ...

    • Geometric configuration around GL 2591 : an infrared reflection nebula and a CS molecular disk 

      Yamashita, T.; Sato, S.; Tamura, M.; Suzuki, H.; Kaifu, N.; Takano, T.; Mountain, C.M.; Moore, T.J.T.; Gatley, I.; Hough, J. (1987)

    • He i 1.083 um Emission and Absorption in DG Tauri: Line Excitations in the Jet, Hot Wind, and Accretion Flow 

      Takami, M.; Chrysostomou, A.; Bailey, J.; Gledhill, T.; Tamura, M.; Terada, H. (2002-03)

    • A high sensitivity polarimeter for the direct detection and characterization of extra-solar planets 

      Hough, J.; Lucas, P.W.; Bailey, J.; Tamura, M. (2003)

    • High-resolution imaging polarimetry of HL Tau and magnetic field structure 

      Lucas, P.W.; Fukagawa, M.; Tamura, M.; Beckford, A. (2004)

    • HL Tau: 3-D Polarisation Modelling and Magnetic Field Structure 

      Lucas, P.W.; Fukagawa, M.; Tamura, M.; Chrysostomou, A.; Beckford, A. (Astronomical Society of the Pacific, 2005)
      We describe 3-dimensional Monte Carlo modelling of HL Tau in the near infrared with aligned non-spherical grains. JHK linear polarimetry with 0.4-0.6 arcsec resolution from Subaru and UKIRT is fitted in detail, providing ...

    • Hα and Hel emission in the jets of pre-main sequence stars : implications for the heating mechanisms 

      Takami, M.; Chrysostomou, A.; Bailey, J.; Gledhill, T.; Tamura, M.; Terada, H. (2003)
      Jets and winds in pre-main sequence (PMS) stars are often heated and ionized, and understanding their heating mechanism is desired to compare UV-to-IR spectral signatures with models and thus investigate their driving ...

    • Identification of the exciting source of Herbig-Haro objects 135 and 136 

      Tamura, M.; Hough, J.; Chrysostomou, A.; Itoh, Y.; Murakawa, K.; Bailey, J. (1997)
      We have identified the exciting source of the Herbig-Haro objects HH135 and 136 by near-infrared polarimetric imaging of the associated extensive reflection nebula. The source is situated at the middle of the two Herbig-Haro ...