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Title: Near-infrared spectroscopy of the Y0 WISEP J173835.52+273258.9 and the Y1 WISE J035000.32–565830.2: The importance of non-equilibrium chemistry

Journal Article · · The Astrophysical Journal (Online)
 [1];  [2];  [3];  [4];  [5];  [6];  [7];  [7]
  1. Gemini Observatory, Hilo, HI (United States)
  2. Maison de la Simulation, CEA-CNRS-INRIA-UPS-UVSQ, USR, Gif-Sur-Yvette (France); Univ. of Exeter, Exeter (United Kingdom)
  3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  4. NASA Ames Research Center, Moffett Field, CA (United States)
  5. Univ. of California, Santa Cruz, CA (United States)
  6. Univ. of Exeter, Exeter (United Kingdom)
  7. Univ. of Exeter, Exeter (United Kingdom); Ecole Normale Superieure de Lyon, CRAL, UMR, CNRS, Lyon Cedex (France)
+ Show Author Affiliations

Here, we present new near-infrared spectra, obtained at Gemini Observatory, for two Y dwarfs: WISE J035000.32–565830.2 (W0350) and WISEP J173835.52+273258.9 (W1738). A FLAMINGOS-2 R = 540 spectrum was obtained for W0350, covering $$1.0\lt \lambda \;\mu {\rm{m}}$$ $$\lt \;1.7$$, and a cross-dispersed Gemini near-infrared spectrograph R = 2800 spectrum was obtained for W1738, covering 0.993–1.087 μm, 1.191–1.305 μm, 1.589–1.631 μm, and 1.985–2.175 μm, in four orders. We also present revised YJH photometry for W1738, using new NIRI Y and J imaging, and a re-analysis of the previously published NIRI H-band images. We compare these data, together with previously published data for late-T and Y dwarfs, to cloud-free models of solar metallicity, calculated both in chemical equilibrium and with disequilibrium driven by vertical transport. We find that for the Y dwarfs, the non-equilibrium models reproduce the near-infrared data better than the equilibrium models. The remaining discrepancies suggest that fine-tuning the CH4/CO and NH3/N2 balance is needed. Improved trigonometric parallaxes would improve the analysis. Despite the uncertainties and discrepancies, the models reproduce the observed near-infrared spectra well. We find that for the Y0, W1738, $${T}_{{\rm{eff}}}=425\pm 25\;{\rm{K}}$$, and log $$g=4.0\pm 0.25$$, and for the Y1, W0350, $${T}_{{\rm{eff}}}=350\pm 25\;{\rm{K}}$$, and log $$g=4.0\pm 0.25$$. W1738 may be metal-rich. Based on evolutionary models, these temperatures and gravities correspond to a mass range for both Y dwarfs of 3–9 Jupiter masses, with W0350 being a cooler, slightly older, version of W1738; the age of W0350 is 0.3–3 Gyr, and the age of W1738 is 0.15–1 Gyr.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
National Aeronautics and Space Administration (NASA); USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1296684
Report Number(s):
LA-UR-16-21256
Journal Information:
The Astrophysical Journal (Online), Vol. 824, Issue 1; ISSN 1538-4357
Publisher:
Institute of Physics (IOP)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 10 works
Citation information provided by
Web of Science

References (71)

Precipitating Condensation Clouds in Substellar Atmospheres journal August 2001
Synthetic Spectra and Mass Determination of the Brown Dwarf Gliese 229B journal July 1996
Accuracy tests of radiation schemes used in hot Jupiter global circulation models journal April 2014
WISE Y DWARFS AS PROBES OF THE BROWN DWARF-EXOPLANET CONNECTION journal February 2014
Fire Spectroscopy of the Ultra-Cool Brown Dwarf, ugps J072227.51–054031.2: Kinematics, Rotation and Atmospheric Parameters journal October 2011
Thin disc, thick disc and halo in a simulated galaxy: Disc galaxy decomposition journal September 2012
THE BROWN DWARF KINEMATICS PROJECT (BDKP). IV. RADIAL VELOCITIES OF 85 LATE-M AND L DWARFS WITH MagE journal September 2015
76 T dwarfs from the UKIDSS LAS: benchmarks, kinematics and an updated space density journal June 2013
A Nongray Theory of Extrasolar Giant Planets and Brown Dwarfs journal December 1997
Beyond the T Dwarfs: Theoretical Spectra, Colors, and Detectability of the Coolest Brown Dwarfs journal October 2003
Methane and ammonia in the near-infrared spectra of late-T dwarfs journal April 2015
Doppler imaging of exoplanets and brown dwarfs journal June 2014
THE DISCOVERY OF Y DWARFS USING DATA FROM THE WIDE-FIELD INFRARED SURVEY EXPLORER ( WISE ) journal November 2011
THREE NEW COOL BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER ( WISE ) AND AN IMPROVED SPECTRUM OF THE Y0 DWARF WISE J041022.71+150248.4 journal April 2014
Extending the Canada-France brown dwarfs survey to the near-infrared: first ultracool brown dwarfs from CFBDSIR journal July 2010
Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects journal September 2013
THE HAWAII INFRARED PARALLAX PROGRAM. I. ULTRACOOL BINARIES AND THE L/T TRANSITION , journal June 2012
Discovery of a Low-Luminosity, Tight Substellar Binary at the t/y Transition journal April 2015
FLAMINGOS-2: the facility near-infrared wide-field imager and multi-object spectrograph for Gemini conference September 2004
Design of the Gemini near-infrared spectrograph conference June 2006
Signatures of Cloud, Temperature, and Gravity from Spectra of the Closest Brown Dwarfs journal July 2014
The role of convection, overshoot, and gravity waves for the transport of dust in M dwarf and brown dwarf atmospheres journal April 2010
Spectroscopic Detection of Carbon Monoxide in two Late-Type t Dwarfs journal April 2009
L ′ and M ′ Photometry of Ultracool Dwarfs journal June 2004
Dust in brown dwarfs: I. Dust formation under turbulent conditions on microscopic scales journal September 2001
The Gemini Near‐Infrared Imager (NIRI)
  • Hodapp, Klaus W.; Jensen, Joseph B.; Irwin, Everett M.
  • Publications of the Astronomical Society of the Pacific, Vol. 115, Issue 814 https://doi.org/10.1086/379669
journal December 2003
Discovery of the y1 Dwarf wise J064723.23–623235.5 journal October 2013
Further Defining Spectral type “y” and Exploring the Low-Mass end of the Field Brown Dwarf mass Function journal June 2012
Near-Infrared Photometry and Spectroscopy of L and T Dwarfs: The Effects of Temperature, Clouds, and Gravity journal June 2004
The Physical Properties of four ∼600 k t Dwarfs journal April 2009
Resolved Spectroscopy of the t8.5 and Y0-0.5 Binary Wisepc J121756.91+162640.2ab journal December 2013
A Comparison of Near-Infrared Photometry and Spectra for y Dwarfs with a new Generation of cool Cloudy Models journal January 2013
Near-Infrared Photometry of y Dwarfs: low Ammonia Abundance and the Onset of Water Clouds journal January 2015
HN Peg B: A Test of Models of the L to T Dwarf Transition journal August 2008
Properties of the t8.5 Dwarf wolf 940 b journal August 2010
3.6–7.9 μm Photometry of L and T Dwarfs and the Prevalence of Vertical Mixing in their Atmospheres journal February 2007
Vertical distribution of disequilibrium species in Jupiter's troposphere journal September 1984
UNIFORM ATMOSPHERIC RETRIEVAL ANALYSIS OF ULTRACOOL DWARFS. I. CHARACTERIZING BENCHMARKS, Gl 570D AND HD 3651B journal July 2015
Cfbdsir J1458+1013b: a very cold (>T10) Brown Dwarf in a Binary System, , journal October 2011
TWO EXTRAORDINARY SUBSTELLAR BINARIES AT THE T/Y TRANSITION AND THE Y -BAND FLUXES OF THE COOLEST BROWN DWARFS , journal September 2012
Solar System Abundances and Condensation Temperatures of the Elements journal July 2003
DISCOVERY OF A ∼250 K BROWN DWARF AT 2 pc FROM THE SUN journal April 2014
Discovery of a Candidate for the Coolest Known Brown Dwarf journal February 2011
On the Cool Side: Modeling the Atmospheres of Brown Dwarfs and Giant Planets journal August 2015
Masses, Radii, and Cloud Properties of the hr 8799 Planets journal July 2012
Atmospheric, Evolutionary, and Spectral Models of the Brown Dwarf Gliese 229 B journal June 1996
Parallaxes and Proper Motions of Ultracool Brown Dwarfs of Spectral Types y and late t journal December 2012
Neglected Clouds in t and y Dwarf Atmospheres journal August 2012
Water Clouds in y Dwarfs and Exoplanets journal May 2014
Chemical kinetics on extrasolar planets journal April 2014
Detection of Abundant Carbon Monoxide in the Brown Dwarf Gliese 229B journal November 1997
Discovery of a new Y dwarf: WISE J030449.03−270508.3 journal September 2014
Large-Amplitude Variations of an l/t Transition Brown Dwarf: Multi-Wavelength Observations of Patchy, High-Contrast Cloud Features journal April 2012
The Infrared Telescope Facility (Irtf) Spectral Library: cool Stars journal November 2009
An Equation of State for Low-Mass Stars and Giant Planets journal July 1995
Molecular Abundances in the Atmosphere of the T Dwarf Gl 229B journal September 2000
The Evolution of L and T Dwarfs in Color‐Magnitude Diagrams journal December 2008
NEW H 2 COLLISION-INDUCED ABSORPTION AND NH 3 OPACITY AND THE SPECTRA OF THE COOLEST BROWN DWARFS journal April 2012
HUBBLE SPACE TELESCOPE SPECTROSCOPY OF BROWN DWARFS DISCOVERED WITH THE WIDE-FIELD INFRARED SURVEY EXPLORER journal May 2015
The distance to the cool T9 brown dwarf ULAS J003402.77-005206.7 journal February 2010
ExoMol line lists – VII. The rotation–vibration spectrum of phosphine up to 1500 K journal November 2014
THE 0.8-14.5 μm SPECTRA OF MID-L TO MID-T DWARFS: DIAGNOSTICS OF EFFECTIVE TEMPERATURE, GRAIN SEDIMENTATION, GAS TRANSPORT, AND SURFACE GRAVITY journal August 2009
A Near-Infrared Spectroscopic Survey of 886 Nearby m Dwarfs journal September 2015
Wise J163940.83–684738.6: a y Dwarf Identified by Methane Imaging journal October 2012
Fingering Convection and Cloudless Models for cool Brown Dwarf Atmospheres journal April 2015
Quenching of Carbon Monoxide and Methane in the Atmospheres of cool Brown Dwarfs and hot Jupiters journal August 2011
A very cool brown dwarf in UKIDSS DR1 journal November 2007
The Spitzer Space Telescope Mission journal September 2004
The Wide-Field Infrared Survey Explorer (Wise): Mission Description and Initial On-Orbit Performance journal November 2010
ExoMol line lists – IV. The rotation–vibration spectrum of methane up to 1500 K journal March 2014
Methane, Carbon Monoxide, and Ammonia in Brown Dwarfs and Self-Luminous Giant Planets journal November 2014

Cited By (6)

The GJ 504 system revisited: Combining interferometric, radial velocity, and high contrast imaging data journal October 2018
A Uniform Retrieval Analysis of Ultra-cool Dwarfs. III. Properties of Y Dwarfs journal May 2019
The Y-type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry, and Near-infrared Spectroscopy journal June 2017
The Y-Type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry and Near-Infrared Spectroscopy text January 2017
A Uniform Retrieval Analysis of Ultracool Dwarfs. III. Properties of Y-Dwarfs text January 2019
The GJ 504 system revisited: Combining interferometric, radial velocity, and high contrast imaging data text January 2018

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Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
molecular processes
stars: brown dwarfs
stars: atmospheres
stars: individual (WISE J035000.32-565830.2
WISEP J173835.52+273258.9)