Characterising brown dwarf companions with IRDIS long-slit spectroscopy: HD 1160 B and HD 19467 B

Abstract

The determination of the fundamental properties (mass, separation, age, gravity and atmospheric properties) of brown dwarf companions allows us to infer crucial informations on their formation and evolution mechanisms. Spectroscopy of substellar companions is available to date only for a limited number of objects (and mostly at very low resolution, R<50) because of technical limitations, i.e., contrast and angular resolution. We present medium resolution (R=350), coronagraphic long-slit spectroscopic observations with SPHERE of two substellar companions, HD 1160 B and HD 19467 B. We found that HD 1160 B has a peculiar spectrum that cannot be fitted by spectra in current spectral libraries. A good fit is possible only considering separately the Y+J and the H spectral band. The spectral type is between M5 and M7. We also estimated a T_eff of 2800-2900 K and a log(g) of 3.5-4.0 dex. The low surface gravity seems to favour young age (10-20 Myr) and low mass (~20 M Jup ) for this object. HD 19467 B is instead a fully evolved object with a T_eff of ~1000 K and log g of ~5.0 dex. Its spectral type is T6+/-1.

14 pages, 14 Figures. Accepted for publication on MNRAS

References in corpus (20)

• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• VOSA: Virtual Observatory SED Analyzer. An application to the Collinder 69 open cluster
• Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• Uniform Atmospheric Retrieval Analysis of Ultracool Dwarfs I: Characterizing Benchmarks, Gl570D and HD3651B
• Extended stellar systems in the solar neighborhood - II. Discovery of a nearby 120° stellar stream in Gaia DR2
• Discovery of a low-mass companion inside the debris ring surrounding the F5V star HD206893
• Helios-r2 -- A new Bayesian, open-source retrieval model for brown dwarfs and exoplanet atmospheres
• Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
• In-depth study of moderately young but extremely red, very dusty substellar companion HD206893B
• Performance of the Near-infrared coronagraphic imager on Gemini-South
• Exoplanet characterization with long slit spectroscopy
• Characterization of the inner disk around HD 141569 A from Keck/NIRC2 L-band vortex coronagraphy
• Supervised Machine Learning for Intercomparison of Model Grids of Brown Dwarfs: Application to GJ 570D and the Epsilon Indi B Binary System
• Direct Spectrum of the Benchmark T dwarf HD 19467 B
• Characterizing HR3549B using SPHERE
• Early Results from VLT-SPHERE: Long-Slit Spectroscopy of 2MASS 0122-2439B, a Young Companion Near the Deuterium Burning Limit
• SCExAO and GPI $YJH$ Band Photometry and Integral Field Spectroscopy of the Young Brown Dwarf Companion to HD 1160
• Orbiting a binary: SPHERE characterisation of the HD 284149 system
• Benchmarking Substellar Evolutionary Models Using New Age Estimates for HD 4747 B and HD 19467 B

Cited by in corpus (14)

• Sulphur dioxide in the mid-infrared transmission spectrum of WASP-39b
• A medium-resolution spectrum of the exoplanet HIP 65426 b
• A comparison of chemical models of exoplanet atmospheres enabled by TauREx 3.1
• Retrieval Study of Brown Dwarfs Across the L-T Sequence
• The ESO SupJup Survey I: Chemical and isotopic characterisation of the late L-dwarf DENIS J0255-4700 with CRIRES${}^{+}$
• Orbital and spectral characterization of the benchmark T-type brown dwarf HD 19467B
• First Observations of the Brown Dwarf HD 19467 B with JWST
• Detectability of satellites around directly imaged exoplanets and brown dwarfs
• Measuring the variability of directly imaged exoplanets using vector Apodizing Phase Plates combined with ground-based differential spectrophotometry
• Exploring the directly imaged HD 1160 system through spectroscopic characterization and high-cadence variability monitoring
• The ExoGRAVITY survey: A K-band spectral library of giant exoplanet and brown dwarf companions
• Distinct Rotational Evolution of Giant Planets and Brown Dwarf Companions
• JWST high-contrast spectroscopy with speckle modelling: Atmospheric retrievals of the T dwarf companion HD 19467 B
• On-sky performance and recent results from the Subaru coronagraphic extreme adaptive optics system