TY - JOUR
T1 - ALMA Discovery of a Disk around the Planetary-mass Companion SR 12 c
AU - Wu, Ya Lin
AU - Bowler, Brendan P.
AU - Sheehan, Patrick D.
AU - Close, Laird M.
AU - Eisner, Joshua A.
AU - Best, William M.J.
AU - Ward-Duong, Kimberly
AU - Zhu, Zhaohuan
AU - Kraus, Adam L.
N1 - Funding Information:
We thank the reviewer for constructive comments. Y.-L.W. is grateful for the support from the Ministry of Science and Technology (MOST 110-2636-M-003-002-) and the Ministry of Education. J.A.E. acknowledges support from NSF awards 1745406 and 1811290. This paper makes use of the following ALMA data: ADS/JAO.ALMA #2019.1.01212.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This research has made use of MATLAB version R2020b.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/5/1
Y1 - 2022/5/1
N2 - We report an Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum detection of the accretion disk around SR 12 c, an ∼11 M Jup planetary-mass companion (PMC) orbiting its host binary at 980 au. This is the first submillimeter detection of a circumplanetary disk around a wide PMC. The disk has a flux density of 127 ± 14 μJy and is not resolved by the ∼0.″1 beam, so the dust disk radius is likely less than 5 au and can be much smaller if the dust continuum is optically thick. If, however, the dust emission is optically thin, then the SR 12 c disk has a comparable dust mass to the circumplanetary disk around PDS 70 c but is about five times lower than that of the ∼12 M Jup free-floating OTS 44. This suggests that disks around bound and unbound planetary-mass objects can span a wide range of masses. The gas mass estimated with an accretion rate of 10-11 M ⊙ yr-1 implies a gas-to-dust ratio higher than 100. If cloud absorption is not significant, a nondetection of 12CO(3-2) implies a compact gas disk around SR 12 c. Future sensitive observations may detect more PMC disks at 0.88 mm flux densities of ≲ 100 μJy.
AB - We report an Atacama Large Millimeter/submillimeter Array 0.88 mm (Band 7) continuum detection of the accretion disk around SR 12 c, an ∼11 M Jup planetary-mass companion (PMC) orbiting its host binary at 980 au. This is the first submillimeter detection of a circumplanetary disk around a wide PMC. The disk has a flux density of 127 ± 14 μJy and is not resolved by the ∼0.″1 beam, so the dust disk radius is likely less than 5 au and can be much smaller if the dust continuum is optically thick. If, however, the dust emission is optically thin, then the SR 12 c disk has a comparable dust mass to the circumplanetary disk around PDS 70 c but is about five times lower than that of the ∼12 M Jup free-floating OTS 44. This suggests that disks around bound and unbound planetary-mass objects can span a wide range of masses. The gas mass estimated with an accretion rate of 10-11 M ⊙ yr-1 implies a gas-to-dust ratio higher than 100. If cloud absorption is not significant, a nondetection of 12CO(3-2) implies a compact gas disk around SR 12 c. Future sensitive observations may detect more PMC disks at 0.88 mm flux densities of ≲ 100 μJy.
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U2 - 10.3847/2041-8213/ac6420
DO - 10.3847/2041-8213/ac6420
M3 - Article
AN - SCOPUS:85129956620
SN - 2041-8205
VL - 930
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L3
ER -