Monte-Carlo radiative transfer simulation of the circumstellar disk of the Herbig Ae star HD 144432

L Chen,D Schertl,R Petrov,Ph Stee,G Weigelt,F Massi,K.-H Hofmann,A Kreplin,F Malbet

doi:10.1051/0004-6361/201424020

Abstract

Studies of pre-transitional disks, with a gap region between the inner infrared-emitting region and the outer disk, are important to improving our understanding of disk evolution and planet formation. Previous infrared interferometric observations have shown hints of a gap region in the protoplanetary disk around the Herbig Ae star HD~144432. We study the dust distribution around this star with two-dimensional radiative transfer modeling. We compare the model predictions obtained via the Monte-Carlo radiative transfer code RADMC-3D with infrared interferometric observations and the {\SED} of HD~144432. The best-fit model that we found consists of an inner optically thin component at $0.21\enDash0.32~\AU$ and an optically thick outer disk at $1.4\enDash10~\AU$. We also found an alternative model in which the inner sub-AU region consists of an optically thin and an optically thick component. Our modeling suggests an optically thin component exists in the inner sub-AU region, although an optically thick component may coexist in the same region. Our modeling also suggests a gap-like discontinuity in the disk of HD~144432.

Highlights

In recent years, a growing number of protoplanetary disks have been found to have a gap region between the inner near-infraredemitting region and the outer disk (e.g., Espaillat et al 2008; Benisty et al 2010; Mulders et al 2011; Honda et al 2012; Maaskant et al 2013; Matter et al 2014)
We compare the model predictions obtained via the Monte-Carlo radiative transfer code RADMC-3D with infrared interferometric observations and the spectral energy distribution of HD 144432
These pre-transitional disks are likely in the intermediate evolutionary stage between an early-stage disk that is optically thick from the dust sublimation radius to the outer edge and a transitional disk, whose inner region is already cleared

Summary

Introduction

A growing number of protoplanetary disks have been found to have a gap region between the inner near-infraredemitting region and the outer disk (e.g., Espaillat et al 2008; Benisty et al 2010; Mulders et al 2011; Honda et al 2012; Maaskant et al 2013; Matter et al 2014). The mechanisms possibly involved in the formation of a gap include dynamical clearing by a giant planet, grain growth, and photoevaporation (Williams & Cieza 2011). These pre-transitional disks are likely in the intermediate evolutionary stage between an early-stage disk that is optically thick from the dust sublimation radius to the outer edge and a transitional disk, whose inner region is already cleared. The strong near-infrared (NIR) excess of this Herbig Ae star is a clear signature of hot dust

Objectives

Findings

Discussion

Conclusion