High-precision Dynamical Masses of Pre-main-sequence Stars with ALMA and Gaia
AffiliationUniv Arizona, Dept Astron
Univ Arizona, Steward Observ
radio lines: stars
stars: fundamental parameters
stars: pre-main sequence
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationPatrick D. Sheehan et al 2019 ApJ 874 136
Rights© 2019. The American Astronomical Society. All rights reserved.
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AbstractThe Keplerian rotation in protoplanetary disks can be used to robustly measure stellar masses at very high precision if the source distance is known. We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of spatially and spectrally resolved (CO)-C-12 (2-1) emission toward the disks around 2MASS J16262774-2527247 (the tertiary companion to ROXs 12 at 5100 au), CT Cha, and DH Tau. We employ detailed modeling of the Keplerian rotation profile, coupled with accurate distances from Gaia, to directly measure the stellar masses with similar to 2% precision. We also compare these direct mass measurements with the masses inferred from evolutionary models, determined in a statistically rigorous way. We find that 2MASS J16262774-2527247 has a mass of 0.535(-)(0.007)(+0.006) M-circle dot and CT Cha has a mass of 0.796(-0.014)(+0.015) M-circle dot, broadly consistent with evolutionary models, although potentially significant differences remain. DH Tau has a mass of 0.101(-0.003)(+0.004) M-circle dot, but it suffers from strong foreground absorption that may affect our mass estimate. The combination of ALMA, Gaia, and codes like pdspy, presented here, can be used to infer the dynamical masses for large samples of young stars and substellar objects, and place constraints on evolutionary models.
VersionFinal published version
SponsorsHeising-Simons Foundation; Homer L. Dodge Endowed Chair; National Science Foundation Graduate Research Fellowship ; NSF AAG grant ; NASA's Science Mission Directorate