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Author Hendler, Nathanial P. ♦ Mulders, Gijs D. ♦ Pascucci, Ilaria ♦ Greenwood, Aaron ♦ Kamp, Inga ♦ Henning, Thomas ♦ Ménard, François ♦ Dent, William R. F. ♦ II, Neal J. Evans
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ BOUNDARY CONDITIONS ♦ DUSTS ♦ DWARF STARS ♦ EMISSION ♦ ENERGY SPECTRA ♦ LUMINOSITY ♦ MASS ♦ PERTURBED ANGULAR CORRELATION ♦ PLANETS ♦ PROTOPLANETS ♦ RADIANT HEAT TRANSFER ♦ SENSITIVITY ♦ SPACE ♦ SPECTROMETERS ♦ T TAURI STARS
Abstract The properties of disks around brown dwarfs and very low mass stars (hereafter VLMOs) provide important boundary conditions on the process of planet formation and inform us about the numbers and masses of planets than can form in this regime. We use the Herschel Space Observatory PACS spectrometer to measure the continuum and [O i] 63 μ m line emission toward 11 VLMOs with known disks in the Taurus and Chamaeleon I star-forming regions. We fit radiative transfer models to the spectral energy distributions of these sources. Additionally, we carry out a grid of radiative transfer models run in a regime that connects the luminosity of our sources with brighter T Tauri stars. We find that VLMO disks with sizes 1.3–78 au, smaller than typical T Tauri disks, fit well the spectral energy distributions assuming that disk geometry and dust properties are stellar mass independent. Reducing the disk size increases the disk temperature, and we show that VLMOs do not follow previously derived disk temperature–stellar luminosity relationships if the disk outer radius scales with stellar mass. Only 2 out of 11 sources are detected in [O i] despite a better sensitivity than was achieved for T Tauri stars, suggesting that VLMO disks are underluminous. Using thermochemical models, we show that smaller disks can lead to the unexpected [O i] 63 μ m nondetections in our sample. The disk outer radius is an important factor in determining the gas and dust observables. Hence, spatially resolved observations with ALMA—to establish if and how disk radii scale with stellar mass—should be pursued further.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-06-01
Publisher Place United States
Journal Astrophysical Journal
Volume Number 841
Issue Number 2


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