A model grid for the reflected light from transition disks

TL;DR

This paper presents a model grid for simulating reflected light from transition disks, aiding in understanding dust properties and disk geometry through comparison with observations.

Contribution

It introduces a Monte Carlo-based model grid for polarized light scattering in protoplanetary disks, providing a diagnostic tool to analyze dust properties and disk structures.

Findings

Models reproduce observed intensity and polarization measurements.

Disk properties can be constrained using diagnostic quantities.

The approach helps determine dust scattering characteristics.

Abstract

The dust in protoplanetary disks is an important ingredient in planet formation and can be investigated with model simulations and quantitative imaging polarimetry of the scattered stellar light. This study explores circumstellar disks with calculations for the intensity and polarization of the reflected light. The photon scattering and absorption by the disk are calculated with a Monte Carlo method for a grid of simple, rotationally symmetric models approximated at each point by a plane-parallel dusty atmosphere. The results of our simple disk models reproduce well the measurements for the intensity $I/I_{\star}$, azimuthal polarization $Q_{\varphi}/I_{\star}$, and fractional polarization $p_{\varphi}$ reported for well-observed transition disks. They describe the dependencies of the scattered radiation on the disk geometry and the dust scattering parameters in detail. Particularly strong constraints on disk properties can be obtained from certain diagnostic quantities. Therefore, they can be used as a diagnostic tool for the analysis of quantitative measurements, specifically in constraining or even determining the scattering properties of the dust particles in disks. Collecting and comparing such information for many systems is required to understand the nature of the scattering dust in planet-forming disks.