Millimeter spectral indices and dust trapping by planets in brown dwarf disks
Author
dc.contributor.author
Pinilla, P.
Author
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Quiroga Núñez, L. H.
Author
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Benisty, Myriam
Author
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Natta, A.
Author
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Ricci, L.
Author
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Henning, Thomas
Author
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Van der Plas, Gerrit
Author
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Birnstiel, T.
Author
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Testi, L.
Author
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Ward Duon, K.
Admission date
dc.date.accessioned
2018-07-09T17:33:03Z
Available date
dc.date.available
2018-07-09T17:33:03Z
Publication date
dc.date.issued
2017
Cita de ítem
dc.identifier.citation
The Astrophysical Journal, 846:70 (10pp), 2017
es_ES
Identifier
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10.3847/1538-4357/aa816f
Identifier
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https://repositorio.uchile.cl/handle/2250/149670
Abstract
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Disks around brown dwarfs (BDs) are excellent laboratories to study the first steps of planet formation in cold and low-mass disk conditions. The radial-drift velocities of dust particles in BD disks higher than in disks around more massive stars. Therefore, BD disks are expected to be more depleted in millimeter-sized grains compared to disks around T Tauri or Herbig Ae/Be stars. However, recent millimeter observations of BD disks revealed low millimeter spectral indices, indicating the presence of large grains in these disks and challenging models of dust evolution. We present 3 mm photometric observations carried out with the IRAM/Plateau de Bure Interferometer (PdBI) of three BD disks in the Taurus star-forming region, which have been observed with ALMA at 0.89 mm. The disks were not resolved and only one was detected with enough confidence (similar to 3.5 sigma) with PdBI. Based on these observations, we obtain the values and lower limits of the spectral index and find low values (alpha(mm) less than or similar to 3.0). We compare these observations in the context of particle trapping by an embedded planet, a promising mechanism to explain the observational signatures in more massive and warmer disks. We find, however, that this model cannot reproduce the current millimeter observations for BD disks, and multiple-strong pressure bumps globally distributed in the disk remain as a favorable scenario to explain observations. Alternative possibilities are that the gas masses in the BD disk are very low (similar to 2 x 10(-3) M-Jup) such that the millimeter grains are decoupled and do not drift, or fast growth of fluffy aggregates.
es_ES
Patrocinador
dc.description.sponsorship
NASA - Space Telescope Science Institute
HST-HF2-51380.001-A
NASA
NAS 5-26555
ANR of France
ANR-16-CE31-0013