Differences in the gas and dust distribution in the transitional disk of a sun-like young star, PDS 70

TL;DR

This study uses ALMA observations to reveal complex gas and dust structures in the transitional disk of PDS 70, including a radial dust gap and gas features with no dust counterparts, suggesting intricate disk dynamics.

Contribution

It provides detailed ALMA observations and modeling of the gas and dust distribution in PDS 70's transitional disk, highlighting new features like azimuthal gas gaps and bridge-like structures.

Findings

Radial dust gap from 15-60 au across all grain sizes.

Gas disk shows azimuthal gaps and bridge features absent in dust.

Model confirms a two-component disk with a 15-60 au dust gap.

Abstract

We present ALMA 0.87 mm continuum, HCO+ J=4--3 emission line, and CO J=3--2 emission line data of the disk of material around the young, Sun-like star PDS 70. These data reveal the existence of a possible two component transitional disk system with a radial dust gap of 0."2 +/- 0."05, an azimuthal gap in the HCO+ J=4--3 moment zero map, as well as two bridge-like features in the gas data. Interestingly these features in the gas disk have no analogue in the dust disk making them of particular interest. We modeled the dust disk using the Monte Carlo radiative transfer code HOCHUNK3D (Whitney et al. 2013) using a two disk components. We find that there is a radial gap that extends from 15-60 au in all grain sizes which differs from previous work.