A High Mass Dusty Disk Candidate: The Case of IRAS 18151-1208

TL;DR

This study presents high-resolution observations of a high mass protostellar object, revealing an elongated dust disk structure perpendicular to the outflow, consistent with scaled-up low mass disk models, and discusses implications for high mass star formation.

Contribution

The paper demonstrates that high mass protostellar disks can be modeled as scaled-up versions of low mass disks using similar density and flaring parameters.

Findings

The outflow is oriented southeast-northwest.

The dust continuum shows elongation perpendicular to the outflow.

Inner 30 AU region is stable under Toomre criterion.

Abstract

Many questions remain regarding the properties of disks around massive prototstars. Here we present the observations of a high mass protostellar object including an elongated dust continuum structure perpendicular to the outflow. Submillimeter Array 230 GHz line and continuum observations of the high mass protostellar object IRAS 18151-1208 along with single dish IRAM 30m observations afford us high spatial resolution (0.8") as well as recovery of the extended emission that gets filtered out by the interferometer. The observations of 12CO confirm the outflow direction to be in the southeast-northwest direction, and the 1.3 mm continuum exhibits an elongation in the direction perpendicular to the outflow. We model the physical parameters of the elongated structure by simultaneously fitting the observed spectral energy distribution (SED) and the brightness profile along the major axis using the 3D Radiative Transfer code MC3D. Assuming a density profile similar to that of a low mass disk, we can also reproduce the observations of this high mass protostellar object. This is achieved by using the same density distribution and flaring parameters as were used in the low mass case, and scaling up the size parameters that successfully modeled the circumstellar disk of several T Tauri stars. We also calculate that a region within the inner 30 AU of such a high mass disk is stable under the Toomre criterion. While we do not rule out other scenarios, we show here that the observations in the high mass regime are consistent with a scaled up version of a low mass disk. Implications on high mass star formation are discussed.