Resolved Gas Interior to the Dust Rings of the HD 141569 Disk

TL;DR

This study presents spatially resolved millimeter observations of the HD 141569 disk, revealing a significant gas reservoir with a specific spatial distribution that influences dust placement, bridging characteristics of primordial and debris disks.

Contribution

It provides the first spatially resolved CO emission data for HD 141569, showing how gas distribution affects dust ring locations in debris disks.

Findings

Gas mass is between primordial and debris disk levels.

Large inner hole in CO gas distribution.

Gas influences dust ring positioning.

Abstract

The disk around HD 141569 is one of a handful of systems whose weak infrared emission is consistent with a debris disk, but still has a significant reservoir of gas. Here we report spatially resolved mm observations of the CO(3-2) and CO(1-0) emission as seen with the SMA and CARMA. We find that the excitation temperature for CO is lower than expected from cospatial blackbody grains, similar to previous observations of analogous systems, and derive a gas mass that lies between that of gas-rich primordial disks and gas-poor debris disks. The data also indicate a large inner hole in the CO gas distribution and an outer radius that lies interior to the outer scattered light rings. This spatial distribution, with the dust rings just outside the gaseous disk, is consistent with the expected interactions between gas and dust in an optically thin disk. This indicates that gas can have a significant effect on the location of the dust within debris disks.