Resolving Protoplanetary Disks at Millimeter Wavelengths by CARMA

TL;DR

This study uses CARMA to observe six protoplanetary disks at millimeter wavelengths, constraining their physical properties and disk structures, and comparing two models to understand dust grain growth and disk evolution.

Contribution

It provides detailed physical characterization of protoplanetary disks using Bayesian inference and compares two disk models, highlighting the advantages of the accretion disk model.

Findings

More extended disks are less flared.

Less massive disks have smaller dust opacity spectral index (beta).

Disks with steeper density gradients have smaller beta.

Abstract

We present continuum observations at 1.3 and 2.7 mm using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) toward six protoplanetary disks in the Taurus molecular cloud: CI Tau, DL Tau, DO Tau, FT Tau, Haro 6-13, and HL Tau. We constrain physical properties of the disks with Bayesian inference using two disk models; flared power-law disk model and flared accretion disk model. Comparing the physical properties, we find that the more extended disks are less flared and that the dust opacity spectral index (beta) is smaller in the less massive disks. In addition, disks with a steeper mid-plane density gradient have a smaller beta, which suggests that grains grow and radially move. Furthermore, we compare the two disk models quantitatively and find that the accretion disk model provides a better fit overall. We also discuss the possibilities of substructures on three extended protoplanetary disks.