Structure of CB 26 Protoplanetary Disk Derived from Millimeter Dust Continuum Maps

TL;DR

This study uses high-resolution millimeter observations and modeling to analyze the structure of the CB 26 protoplanetary disk, revealing an inner dust-free region and detailed disk parameters.

Contribution

It presents a detailed modeling approach combining observations and theoretical simulations to derive the disk's physical parameters and structure.

Findings

Inner dust-free region of ~35 AU identified

Disk inclination determined to be 78 degrees

No evidence for dust growth beyond 0.02 cm

Abstract

Observations of the circumstellar disk in the Bok globule CB 26 at 110, 230, and 270 GHz are presented together with the results of the simulations and estimates of the disk parameters. These observations were obtained using the SMA, IRAM Plateau de Bure, and OVRO interferometers. The maps have relatively high angular resolutions (0.4-1"), making it possible to study the spatial structure of the gas-dust disk. The disk parameters are reconstructed via a quantitative comparison of observational and theoretical intensity maps. The disk model used to construct the theoretical maps is based on the assumption of hydrostatic and radiative equilibrium in the vertical direction, while the radial surface density profile is described phenomenologically. The system of equations for the transfer of the infrared and ultraviolet radiation is solved in the vertical direction, in order to compute the thermal structure of the disk. The disk best-fit parameters are derived for each map and all the maps simultaneously, using a conjugate gradient method. The degrees of degeneracy of the parameters describing the thermal structure and density distribution of the disk are analyzed in detail. All three maps indicate the presence of an inner dust-free region with a radius of approximately 35 AU, in agreement with the conclusions of other studies. The inclination of the disk is 78 deg, which is smaller than the value adopted in our earlier study of rotating molecular outflows from CB 26. The model does not provide any evidence for the growth of dust particles above a_max=0.02 cm.