The Onset of Methane in L Dwarfs

Abstract

We have detected weak absorption features produced by the strong nu(3) methane band at 3.3 microns in two L dwarfs, 2MASSW J1507476-162738 and 2MASSI J0825196+211552, classified by Kirkpatrick et al. (2000) as spectral types L5 and L7.5 respectively. These absorptions occur in objects warmer than any in which methane previously has been detected, and mark the first appearance of methane in the ultracool star-to-brown dwarf spectral sequence.

12 pages, 2 figures; accepted by ApJ Letters

References in corpus (5)

• Sixty-seven Additional L Dwarfs Discovered by the Two Micron All Sky Survey (2MASS)
• An Effective Temperature Scale for Late M and L Dwarfs, from Resonance Absorption Lines of CsI and RbI
• The Missing Link: Early Methane ("T") Dwarfs in the Sloan Digital Sky Survey
• The Discovery of a Field Methane Dwarf from Sloan Digital Sky Survey Commissioning Data
• The Discovery of a Second Field Methane Brown Dwarf from Sloan Digital Sky Survey Commissioning Data

Cited by in corpus (60)

• The Theory of Brown Dwarfs and Extrasolar Giant Planets
• An Infrared Spectroscopic Sequence of M, L and T Dwarfs
• Near-Infrared Photometry and Spectroscopy of L and T Dwarfs: the Effects of Temperature, Clouds, and Gravity
• L' and M' Photometry of Ultracool Dwarfs
• Towards Spectral Classification of L and T Dwarfs: Infrared and Optical Spectroscopy and Analysis
• The Spectra of T Dwarfs I: Near-Infrared Data and Spectral Classification
• Infrared Photometry of Late-M, L, and T Dwarfs
• Infrared Spectra and Spectral Energy Distributions of Late-M- and L-Dwarfs
• An accurate, extensive, and practical line list of methane for the HITEMP database
• A search for L dwarf binary systems
• Spitzer Infrared Spectrograph Observations of M, L, and T Dwarfs
• Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets
• The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 Micron Spectrum of the Planetary-Mass Companion VHS 1256-1257 b
• Identification of 1.4 Million AGNs in the Mid-Infrared using WISE Data
• Retrieval of atmospheric properties of cloudy L dwarfs
• New H2 collision-induced absorption and NH3 opacity and the spectra of the coolest brown dwarfs
• A Study of the Diverse T Dwarf Population Revealed by WISE
• Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3$\pi$ Survey
• The Galactic disk mass-budget : II. Brown dwarf mass-function and density
• Infrared Observations and Modeling of one of the Coolest T Dwarfs, Gl 570D
• Physical and Spectral Characteristics of the T8 and Later-Type Dwarfs
• 3.6-7.9 um Photometry of L and T Dwarfs and the Prevalence of Vertical Mixing in their Atmospheres
• The First Ultra-Cool Brown Dwarf Discovered by the Wide-field Infrared Survey Explorer
• Magellan Adaptive Optics first-light observations of the exoplanet beta Pic b. II. 3-5 micron direct imaging with MagAO+Clio, and the empirical bolometric luminosity of a self-luminous giant planet
• The AllWISE Motion Survey, Part 2
• Chemistry of Low Mass Substellar Objects
• AKARI Observations of Brown Dwarfs. III. CO, CO2 and CH4 Fundamental Bands and Physical Parameters
• AKARI Observations of Brown Dwarfs I.: CO and CO_2 Bands in the Near-Infrared Spectra
• Keck NIRC Observations of Planetary-mass Candidate Members in the sigma Orionis Open Cluster
• A Clear View of a Cloudy Brown Dwarf Companion from High-Resolution Spectroscopy
• Spectroscopic Detection of Carbon Monoxide in Two Late-type T Dwarfs
• The Gaia Ultracool Dwarf Sample. I. Known L and T dwarfs and the first Gaia data release
• Dust in the Photospheric Environment II. Effect on the Near Infrared Spectra of L and T Dwarfs
• Methane and Ammonia in the near-infrared spectra of late T dwarfs
• Parallax and Luminosity Measurements of an L Subdwarf
• From cold to hot irradiated gaseous exoplanets: Fingerprints of chemical disequilibrium in atmospheric spectra
• Exoplanet Chemistry
• The Dawes Review 3: The Atmospheres of Extrasolar Planets and Brown Dwarfs
• SDSS J141624.08+134826.7: Blue L Dwarfs and Non-Equilibrium Chemistry
• Methane in Analogs of Young Directly Imaged Exoplanets
• A 1.46-2.48 $\mu$m Spectroscopic Atlas of a T6 Dwarf (1060 K) Atmosphere with IGRINS: First Detections of H${}_2$S and H${}_2$, and Verification of H${}_2$O, CH${}_4$, and NH${}_3$ Line Lists
• The role of clouds on the depletion of methane and water dominance in the transmission spectra of irradiated exoplanets
• Effective Temperatures of late L dwarfs and the onset of Methane signatures
• Detection of new strongly variable brown dwarfs in the L/T transition
• L-Band Photometry of L and T Dwarfs
• Atomic lines in infrared spectra for ultracool dwarfs
• Near-Infrared Spectroscopy of Brown Dwarfs: Methane and the Transition between the L and T Spectral Types
• CORMASS: A Compact and Efficient NIR Spectrograph for Studying Low-Mass Objects
• A Methane Imaging Survey for T Dwarf Candidates in Rho Ophiuchi
• Convective dynamics and disequilibrium chemistry in the atmospheres of giant planets and brown dwarfs
• H and K Band Methane Features in an L Dwarf, 2MASS 0920+35
• The 2MASS Wide-Field T Dwarf Search. V. Discovery of a T Dwarf via Methane Imaging
• The Future of Ultracool Dwarf Science with JWST
• L-band Spectroscopy with Magellan-AO/Clio2: First Results on Young Low-Mass Companions
• On-Sky Operations with the ALES Integral Field Spectrograph
• Mapping the Skies of Ultracool Worlds: Detecting Storms and Spots with Extremely Large Telescopes
• A Unified Spectroscopic and Photometric Model to Infer Surface Inhomogeneity: Application to Luhman 16B
• The Classification of T Dwarfs
• $L$-band Spectra of Young Brown Dwarfs
• Infrared observations of a mid-L dwarf with strong H$\alpha$ emission