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Evolution of Young Brown Dwarf Disks in the Mid-Infrared

Michael F. Sterzik·Ilaria Pascucci·Daniel Apai·Nicole van der Bliek·Cornelis P. Dullemond
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Abstract

We have imaged two bona-fide brown dwarfs with TReCS/GEMINI-S and find mid-infrared excess emission that can be explained by optically thick dust disk models. In the case of the young ($\approx$2Myr) Cha H$α$1 we measure fluxes at 10.4$μ$m and 12.3$μ$m that are fully consistent with a standard flared disk model and prominent silicate emission. For the $\approx$ 10Myr old brown dwarf 2MASS1207-3932 located in the TW Hydrae association we find excess emission at 8.7$μ$m and 10.4$μ$m with respect to its photosphere, and confirm disk accretion as likely cause of its strong activity. Disks around brown dwarfs likely last at least as long as their low-mass stellar counterparts in the T-Tauri phase. Grain growth, dust settling, and evolution of the geometry of brown dwarfs disks may appear on a timescale of 10Myr and can be witnessed by observations in the mid-infrared.

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Michael F. Sterzik, Ilaria Pascucci, Daniel Apai, Nicole van der Bliek, Cornelis P. Dullemond. 2004-08-30. Evolution of Young Brown Dwarf Disks in the Mid-Infrared. https://doi.org/10.1051/0004-6361%3A20041502

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