Modeling the accretion disk around the High-mass protostar GGD 27-MM1

N. Añez López ... [et al.].

Serie: Trabajos publicados del IAR ; no. 1530

Resumen: Recent high angular resolution (≃40 mas) ALMA observations at 1.14 mmresolve a compact (R ≃ 200 au), flattened dust structure perpendicularto the HH 80â"€81 jet emanating from the GGD 27-MM1 high-mass protostar,making it a robust candidate for a true accretion disk. The jetâ"€disksystem (HH 80â"€81/GGD 27-MM1) resembles those found in association withlow- and intermediate-mass protostars. We present radiative transfermodels that fit the 1.14 mm ALMA dust image of this disk, which allow usto obtain its physical parameters and predict its density andtemperature structure. Our results indicate that this accretion disk iscompact (R _disk ≃ 170 au) and massive (≃5 M _☉), atabout 20% of the stellar mass of ≃20 M _☉. We estimate thetotal dynamical mass of the starâ"€disk system from the molecular lineemission, finding a range between 21 and 30 M _☉, which isconsistent with our model. We fit the density and temperature structuresfound by our model with power-law functions. These results suggest thataccretion disks around massive stars are more massive and hotter thantheir low-mass siblings, but they still are quite stable. We alsocompare the temperature distribution in the GGD 27â"€MM1 disk with thatfound in low- and intermediate-mass stars and discuss possibleimplications for the water snow line. We have also carried out a studyof the distance based on Gaia DR2 data and the population of youngstellar objects in this region and from the extinction maps. We concludethat the source distance is within 1.2 and 1.4 kpc, closer than what wasderived in previous studies (1.7 kpc