TY - JOUR
T1 - ALMA OBSERVATIONS of the LARGEST PROTO-PLANETARY DISK in the ORION NEBULA, 114-426
T2 - A CO SILHOUETTE
AU - Bally, John
AU - Mann, Rita K.
AU - Eisner, Josh
AU - Andrews, Sean M.
AU - Francesco, James Di
AU - Hughes, Meredith
AU - Johnstone, Doug
AU - Matthews, Brenda
AU - Ricci, Luca
AU - Williams, Jonathan P.
N1 - Publisher Copyright:
© 2015. The American Astronomical Society. All rights reserved..
PY - 2015/7/20
Y1 - 2015/7/20
N2 - We present ALMA observations of the largest protoplanetary disk in the Orion Nebula, 114-426. Detectable 345 GHz (856 μm) dust continuum is produced only in the 350 AU central region of the ∼1000 AU diameter silhouette seen against the bright background in Hubble Space Telescope images. Assuming optically thin dust emission at 345 GHz, a gas-to-dust ratio of 100, and a grain temperature of 20 K, the disk gas-mass is estimated to be Jupiter masses. If most solids and ices have been incorporated into large grains, however, this value is a lower limit. The disk is not detected in dense-gas tracers such as HCO+ J = 4-3, HCN J = 4-3, or CS = 7-6. These results may indicate that the 114-426 disk is evolved and depleted in some light organic compounds found in molecular clouds. The CO J = 3-2 line is seen in absorption against the bright 50-80 K background of the Orion A molecular cloud over the full spatial extent and a little beyond the dust continuum emission. The CO absorption reaches a depth of 27 K below the background CO emission at VLSR 6.7 km s ∼ 0.″52 (210 AU) northeast and 12 K below the background CO emission at VLSR ≈ 9.7 km s ∼ 0.″34 (140 AU) southwest of the suspected location of the central star, implying that the embedded star has a mass less than 1 M.·
AB - We present ALMA observations of the largest protoplanetary disk in the Orion Nebula, 114-426. Detectable 345 GHz (856 μm) dust continuum is produced only in the 350 AU central region of the ∼1000 AU diameter silhouette seen against the bright background in Hubble Space Telescope images. Assuming optically thin dust emission at 345 GHz, a gas-to-dust ratio of 100, and a grain temperature of 20 K, the disk gas-mass is estimated to be Jupiter masses. If most solids and ices have been incorporated into large grains, however, this value is a lower limit. The disk is not detected in dense-gas tracers such as HCO+ J = 4-3, HCN J = 4-3, or CS = 7-6. These results may indicate that the 114-426 disk is evolved and depleted in some light organic compounds found in molecular clouds. The CO J = 3-2 line is seen in absorption against the bright 50-80 K background of the Orion A molecular cloud over the full spatial extent and a little beyond the dust continuum emission. The CO absorption reaches a depth of 27 K below the background CO emission at VLSR 6.7 km s ∼ 0.″52 (210 AU) northeast and 12 K below the background CO emission at VLSR ≈ 9.7 km s ∼ 0.″34 (140 AU) southwest of the suspected location of the central star, implying that the embedded star has a mass less than 1 M.·
KW - circumstellar matter
KW - protoplanetary disks
KW - stars: pre-main sequence
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U2 - 10.1088/0004-637X/808/1/69
DO - 10.1088/0004-637X/808/1/69
M3 - Article
AN - SCOPUS:84937809549
SN - 0004-637X
VL - 808
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 69
ER -