Abstract:  Protoplanetary disk gas mass remains one of the most difficult 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. Further, recent surveys reveal many disks have low CO-to-dust ratios, suggestive of substantial chemical evolution. Thus, determining the basic disk properties of disk mass, temperature, and CO abundance requires the use of multiple tracers. In this talk I will discuss results from my recent study of the protoplanetary disk GM Aurigae as part of the ALMA large program “Molecules with ALMA at Planet-forming Scales.” Using new and archival ALMA observations, we construct a disk physical/chemical model which reasonably reproduces the spatially resolved CO isotopologue emission, millimeter dust continuum, and the unresolved HD detection from Herschel. Our best fit model favors a large, cold protoplanetary disk with a mass between 0.2 and 0.3 solar masses. 

Host:  Ian Czekala

Please click the link to join the webinar: https://psu.zoom.us/j/96060188956