49 new T dwarfs identified using methane imaging

Abstract

We present the discovery of 49 new photometrically classified T dwarfs from the combination of large infrared and optical surveys combined with follow-up TNG photometry. We used multi-band infrared and optical photometry from the UKIRT and Sloan Digital Sky Surveys to identify possible brown dwarf candidates, which were then confirmed using methane filter photometry. We have defined a new photometric conversion between CH4s - CH4l colour and spectral type for T4 to T8 brown dwarfs based on a part of the sample that has been followed up using methane photometry and spectroscopy. Using methane differential photometry as a proxy for spectral type for T dwarfs has proved to be a very efficient technique. Of a subset of 45 methane selected brown dwarfs that were observed spectroscopically, 100% were confirmed as T dwarfs. Future deep imaging surveys will produce large samples of faint brown dwarf candidates, for which spectroscopy will not be feasible. When broad wavelength coverage is unavailable, methane imaging offers a means to efficiently classify candidates from such surveys using just a pair of near-infrared images.

16 pages, 5 figures. MNRAS accepted

References in corpus (30)

• The Sloan Digital Sky Survey: Technical Summary
• Validation of the new Hipparcos reduction
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• The UKIRT Infrared Deep Sky Survey ZYJHK Photometric System: Passbands and Synthetic Colours
• Initial Performance of the NEOWISE Reactivation Mission
• The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition
• A Unified Near Infrared Spectral Classification Scheme for T Dwarfs
• The Mauna Kea Observatories Near-Infrared Filter Set. II. Specifications for a New JHKL'M' Filter Set for Infrared Astronomy
• The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)
• A Catalog of Northern Stars With Annual Proper Motions Larger Than 0.15 Seconds of Arc (LSPM catalog - North)
• The Luminosity and Mass Functions of Low-Mass Stars in the Galactic Disk: II. The Field
• Low-Mass Dwarf Template Spectra from the Sloan Digital Sky Survey
• Science performance of Gaia, ESA's space-astrometry mission
• A Catalog of Spectroscopically Identified White Dwarf Stars in the First Data Release of the Sloan Digital Sky Survey
• Hubble Space Telescope NICMOS Observations of T Dwarfs: Brown Dwarf Multiplicity and New Probes of the L/T Transition
• The Gemini NICI Planet-Finding Campaign: The Frequency of Planets around Young Moving Group Stars
• Sloan Low-Mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs
• Seventy six T dwarfs from the UKIDSS LAS: benchmarks, kinematics and an updated space density
• The 2MASS Wide-Field T Dwarf Search. IV Unting out T dwarfs with Methane Imaging
• Forty seven new T dwarfs from the UKIDSS Large Area Survey
• Fifteen new T dwarfs discovered in the UKIDSS Large Area Survey
• The properties of the T8.5p dwarf Ross 458C
• The TNG Near Infrared Camera Spectrometer
• Probabilistic selection of high-redshift quasars
• Young T-Dwarf Candidates in IC 348
• A Detailed Model Atmosphere Analysis of Cool White Dwarfs in the Sloan Digital Sky Survey
• Photometric brown-dwarf classification. I. A method to identify and accurately classify large samples of brown dwarfs without spectroscopy
• Two new ultra-cool benchmark systems from WISE+2MASS
• A 1500 deg${}^2$ Near Infrared Proper Motion Catalogue from the UKIDSS Large Area Survey

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• A Search for L/T Transition Dwarfs With Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries
• Primeval very low-mass stars and brown dwarfs - VI. Population properties of metal-poor degenerate brown dwarfs
• New Y and T dwarfs from WISE identified by Methane Imaging
• The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
• NICMOS Kernel-Phase Interferometry I: Catalogue of Brown Dwarfs Observed in F110W and F170M
• Large Scale Searches for Brown Dwarfs and Free-Floating Planets