Detection of strong activity in the eclipsing binary brown dwarf 2MASSJ05352184-0546085 - A possible explanation for the temperature reversal

Abstract

We show high resolution spectra of the eclipsing brown dwarf binary 2MASSJ05352184-0546085 taken at the two opposite radial velocity maxima. Comparisons of the TiO bands to model and template spectra are fully consistent with the temperatures previously derived for this system. In particular, the reversal of temperatures with mass - in which the higher-mass primary is cooler than its companion - is confirmed. We measure the projected rotation velocities of the compononents; the primary is rotating at least twice as rapidly as the secondary. At the two radial velocity maxima, Halpha emission lines of both components stick out to either sides of the Halpha central wavelength, which is dominated by nebula emission. This enables us to model the individual Halpha lines of the primary and the secondary. We find that the Halpha emission from the primary is at least 7 times stronger than the emission from the secondary. We conclude that the temperature reversal is very likely due to strong magnetic fields inhibiting convection on the primary.

accepted for ApJ Letters

References in corpus (10)

• The Limiting Effects of Dust in Brown Dwarf Model Atmospheres
• L' and M' Photometry of Ultracool Dwarfs
• Evolution of low-mass star and brown dwarf eclipsing binaries
• Spectroscopic Properties of Cool Stars in the SDSS: An Analysis of Magnetic Activity and a Search for Subdwarfs
• A reappraisal of the chemical composition of the Orion nebula based on VLT echelle spectrophotometry
• The First Direct Measurements of Magnetic Fields on Very Low-Mass Stars
• A Surprising Reversal of Temperatures in the Brown-Dwarf Eclipsing Binary 2MASS J05352184-0546085
• Measuring Fundamental Parameters of Substellar Objects. I: Surface Gravities
• The First High-Resolution Spectra of 1.3 L Subdwarfs
• Calibrating models of ultralow-mass stars

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