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 isotopolog HD are used. However, relying on disk mass measurements from any single tracer requires assumptions about the tracer's abundance relative to \hh\ 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 isotopolog emission from eleven 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 solar masses, 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.

18 pages, 12 figures

References in corpus (20)

• The NumPy array: a structure for efficient numerical computation
• Molecules with ALMA at Planet-forming Scales (MAPS) I: Program Overview and Highlights
• Protoplanetary disk masses from CO isotopologues line emission
• Mass measurements in protoplanetary disks from hydrogen deuteride
• Molecules with ALMA at Planet-forming Scales (MAPS) V: CO gas distributions
• Mass inventory of the giant-planet formation zone in a solar nebula analog
• Molecules with ALMA at Planet-forming Scales (MAPS) IV: Emission Surfaces and Vertical Distribution of Molecules
• An ALMA Survey of CO isotopologue emission from Protoplanetary Disks in Chamaeleon I
• Water vapor distribution in protoplanetary disks
• High gas/dust size ratio indicating efficient radial drift in the mm-faint CX Tau disk
• Chemistry in Protoplanetary Disks: the gas-phase CO/H2 ratio and the Carbon reservoir
• HD far infrared emission as a measure of protoplanetary disk mass
• New Constraints From Dust Lines On The Surface Densities Of Protoplanetary Disks
• The TW Hya Rosetta Stone Project III: Resolving the Gaseous Thermal Profile of the Disk
• Mass constraints for 15 protoplanetary disks from HD 1-0
• 13C17O suggests gravitational instability in the HL Tau disc
• Turbulent-diffusion Mediated CO Depletion in Weakly Turbulent Protoplanetary disks
• FUV Irradiation and the Heat Signature of Accretion in Protoplanetary Disk Atmospheres
• Hiding Signatures of Gravitational Instability in Protoplanetary Discs with Planets
• Panchromatic Imaging of a Transitional Disk: The Disk of GM Aur in Optical and FUV Scattered Light

Cited by in corpus (2)

• Molecules with ALMA at Planet-forming Scales (MAPS) I: Program Overview and Highlights
• Molecules with ALMA at Planet-forming Scales (MAPS). VII. Sub-stellar O/H and C/H and super-stellar C/O in planet feeding gas