ALMA OBSERVATIONS OF {rho}-Oph 102: GRAIN GROWTH AND MOLECULAR GAS IN THE DISK AROUND A YOUNG BROWN DWARF

Journal Article · Thu Dec 20 04:00:00 EST 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/761/2/L20· OSTI ID:22078375

Ricci, L ^[1]; Testi, L ^[2]; Natta, A ^[3]; Scholz, A ^[4]

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1. Department of Astronomy, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States)
2. European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany)
3. INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy)
4. School of Cosmic Physics, Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

We present ALMA continuum and spectral line observations of the young brown dwarf {rho}-Oph 102 at about 0.89 mm and 3.2 mm. We detect dust emission from the disk at these wavelengths and derive an upper limit on the radius of the dusty disk of {approx}40 AU. The derived variation of the dust opacity with frequency in the millimeter (mm) provides evidence for the presence of mm-sized grains in the disk's outer regions. This result demonstrates that mm-sized grains are found even in the low-density environments of brown dwarf disks and challenges our current understanding of dust evolution in disks. The CO map at 345 GHz clearly reveals molecular gas emission at the location of the brown dwarf, indicating a gas-rich disk as typically found for disks surrounding young pre-main-sequence stars. We derive a disk mass of {approx}0.3%-1% of the mass of the central brown dwarf, similar to the typical values found for disks around more massive young stars.

• OSTI ID: 22078375
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 761; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC DUST
DWARF STARS
EMISSION
GALACTIC EVOLUTION
GHZ RANGE
GRAIN GROWTH
MAIN SEQUENCE STARS
MAPS
MASS
MOLECULES
OPACITY
WAVELENGTHS