Molecules with ALMA at planet-forming scales. XX. The massive disk around GM Aurigae
Abstract
Gas mass remains one of the most difficult protoplanetary disk properties to constrain. With much of the protoplanetary disk too cold for the main gas constituent, H2, to emit, alternative tracers such as dust, CO, or the H2 isotopologue HD are used. However, relying on disk mass measurements from any single tracer requires assumptions about the tracer's abundance relative to H2 and the disk temperature structure. Using new Atacama Large Millimeter/submillimeter Array (ALMA) observations from the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program as well as archival ALMA observations, we construct a disk physical/chemical model of the protoplanetary disk GM Aur. Our model is in good agreement with the spatially resolved CO isotopologue emission from 11 rotational transitions with spatial resolution ranging from 0"15 to 0"46 (24-73 au at 159 pc) and the spatially unresolved HD J = 1-0 detection from Herschel. Our best-fit model favors a cold protoplanetary disk with a total gas mass of approximately 0.2 M⊙, a factor of 10 reduction in CO gas inside roughly 100 au and a factor of 100 reduction outside of 100 au. Despite its large mass, the disk appears to be on the whole gravitationally stable based on the derived Toomre Q parameter. However, the region between 70 and 100 au, corresponding to one of the millimeter dust rings, is close to being unstable based on the calculated Toomre Q of <1.7. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.
Citation
Schwarz , K R , Calahan , J K , Zhang , K , Alarcón , F , Aikawa , Y , Andrews , S M , Bae , J , Bergin , E A , Booth , A S , Bosman , A D , Cataldi , G , Cleeves , L I , Czekala , I , Huang , J , Ilee , J D , Law , C J , Le Gal , R , Liu , Y , Long , F , Loomis , R A , Macías , E , McClure , M , Ménard , F , Öberg , K I , Teague , R , van Dishoeck , E , Walsh , C & Wilner , D J 2021 , ' Molecules with ALMA at planet-forming scales. XX. The massive disk around GM Aurigae ' , Astrophysical Journal Supplement Series , vol. 257 , no. 1 , 20 . https://doi.org/10.3847/1538-4365/ac143b
Publication
Astrophysical Journal Supplement Series
Status
Peer reviewed
ISSN
0067-0049Type
Journal article
Rights
Copyright © 2021. The American Astronomical Society. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at https://doi.org/10.3847/1538-4365/ac143b.
Description
Funding: K.R.S., K.Z., J.B., J.H., and I.C. acknowledge the support of NASA through Hubble Fellowship Program grants HST-HF2-51419.001, HST-HF2-51401.001, HST-HF2-51427.001-A, HST-HF2-51460.001-A, and HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC and UKRI (grant numbers ST/R000549/1, ST/T000287/1, MR/T040726/1).Collections
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