Spectral characterization of newly detected young substellar binaries with SINFONI

Abstract

We observe 14 young low-mass substellar objects in young moving groups using the SINFONI IFS with LGS-AO to detect and characterize 3 candidate binary systems. Together with the adopted young moving group ages we employ isochrones from substellar evolutionary models to estimate individual masses for the binaries. We find 2MASS J15104786-2818174 to be part of the $\approx 30-50$ Myr Argus moving group and composed of a $34-48M_{\mathrm{Jup}}$ primary brown dwarf with spectral type M$9\gamma$ and a fainter $15-22M_{\mathrm{Jup}}$ companion, separated by $\approx 100$ mas. 2MASS J22025794-5605087 is identified as an almost equal-mass binary in the AB Dor moving group, with a projected separation of $\approx 60$ mas. Both components share spectral type M$9\gamma /\beta$, which with the adopted age of $120-200$ Myr yields individual masses between $50-68M_{\mathrm{Jup}}$. The observations of 2MASS J15474719-2423493 are of lesser quality and we obtain no spectral characterization for the target, but resolve two components separated by $\approx 170$ mas which with the predicted young field age of $30-50$ Myr yields individual masses below $20M_{\mathrm{Jup}}$. Out of the 3 candidate binary systems, 2MASS J22025794-5605087 has unambiguous spectroscopic signs of being a bona-fide binary, while the other two will require second-epoch confirmation. The small projected separations between the binary components corresponds to physical separations of $\approx 4-7$ AU, allowing for astrometric monitoring of just a few years in order to generate constrained orbital fits and dynamical masses for the systems. In combination with their young ages, these binaries will prove to be excellent benchmarks for calibrating substellar evolutionary models down to a very low-mass regime.

arXiv comment17 pages, 14 figures

References in corpus (59)

• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Gaia Data Release 2: The astrometric solution
• A Survey of Stellar Families: Multiplicity of Solar-Type Stars
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• Stellar Multiplicity
• Automated data reduction workflows for astronomy
• A Giant Planet Candidate near a Young Brown Dwarf
• The Formation of Brown Dwarfs as Ejected Stellar Embryos
• The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
• Bayesian analysis to identify new star candidates in nearby young stellar kinematic groups
• Atmospheric Parameters of Field L and T Dwarfs
• Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey
• The Deuterium-Burning Mass Limit for Brown Dwarfs and Giant Planets
• Multiplicity of Nearby Free-floating Ultra-cool Dwarfs: a HST-WFPC2 search for companions
• BANYAN. II. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups With Previously Known Signs of Youth
• The "Mysterious" Origin of Brown Dwarfs
• Population Properties of Brown Dwarf Analogs to Exoplanets
• Brown Dwarfs and the TW Hya Association
• The Formation and Early Evolution of Low-mass Stars and Brown Dwarfs
• Discovery of a Very Young Field L Dwarf, 2MASS J01415823-4633574
• BANYAN. VII. A New Population of Young Substellar Candidate Members of Nearby Moving Groups from the BASS Survey
• The AstraLux Large M-dwarf Multiplicity Survey
• Hubble Space Telescope NICMOS Observations of T Dwarfs: Brown Dwarf Multiplicity and New Probes of the L/T Transition
• A Stellar Census of the Tucana-Horologium Moving Group
• Discovery of a Binary Brown Dwarf at 2 Parsecs from the Sun
• Dynamical Mass of the Substellar Benchmark Binary HD 130948BC
• A library of near-infrared integral field spectra of young M-L dwarfs
• Constraining the initial entropy of directly-detected exoplanets
• A VLT/NACO Survey for Triple and Quadruple Systems among Visual Pre-Main Sequence Binaries
• The Carina-Near Moving Group
• On the Distribution of Orbital Eccentricities for Very Low-Mass Binaries
• Brown dwarfs and low-mass stars in the Pleiades and Praesepe:- Membership and binarity
• The GALEX Nearby Young-Star Survey
• A Search for L/T Transition Dwarfs With Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries
• Two Extraordinary Substellar Binaries at the T/Y Transition and the Y-Band Fluxes of the Coolest Brown Dwarfs
• Constraining the multiplicity statistics of the coolest brown dwarfs: binary fraction continues to decrease with spectral type
• WISE Brown Dwarf Binaries: The Discovery of a T5+T5 and a T8.5+T9 System
• Search for associations containing young stars (SACY):II. Chemical abundances of stars in 11 young Associations in the Solar neighborhood
• The Brown Dwarf Kinematics Project (BDKP). IV. Radial Velocities of 85 Late-M and L dwarfs with MagE
• Multiple Star Formation to the Bottom of the IMF
• On the frequency of close binary systems among very low-mass stars and brown dwarfs
• The AstraLux Multiplicity Survey: Extension to Late M-dwarfs
• New Evidence for a Substellar Luminosity Problem: Dynamical Mass for the Brown Dwarf Binary Gl 417BC
• The Young L Dwarf 2MASS J11193254-1137466 is a Planetary-Mass Binary
• Brown dwarf formation by binary disruption
• Characterization of Low-mass, Wide-separation Substellar Companions to Stars in Upper Scorpius: Near-infrared Photometry and Spectroscopy
• Discovery of a Low-Luminosity, Tight Substellar Binary at the T/Y Transition
• The Hawaii Infrared Parallax Program. III. 2MASS J0249-0557 c: A Wide Planetary-mass Companion to a Low-mass Binary in the beta Pic Moving Group
• A Brown Dwarf Census from the SIMP Survey
• Improving dynamical mass constraints for intermediate-period substellar companions using Gaia DR2
• SPOTS: The Search for Planets Orbiting Two Stars. III. Complete Sample and Statistical Analysis
• A pilot survey of the binarity of Massive Young Stellar Objects with $K$ band adaptive optics
• Isochronal age-mass discrepancy of young stars: SCExAO/CHARIS integral field spectroscopy of the HIP 79124 triple system
• Optical Spectra of Ultracool Dwarfs with the Southern African Large Telescope
• The discrepancy between dynamical and theoretical mass in the triplet-system 2MASS J10364483+1521394
• WISE J061213.85-303612.5: a new T-dwarf binary candidate

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• JWST/NIRCam discovery of the first Y+Y brown dwarf binary: WISE J033605.05$-$014350.4
• Updated orbital monitoring and dynamical masses for nearby M-dwarf binaries
• Characterising Young Visual M-dwarf Binaries with Near-Infrared Integral Field Spectra
• Discovery of 34 low-mass comoving systems using NOIRLab Source Catalog DR2