ALMA Observations of HD141569's Circumstellar Disk

ALMA Observations of HD141569's Circumstellar Disk

Authors:

White et al

Abstract:

We present ALMA band 7 (345 GHz) continuum and 12CO(J = 3-2) observations of the circumstellar disk surrounding HD141569. At an age of about 5 Myr, the disk has a complex morphology that may be best interpreted as a nascent debris system with gas. Our 870 μm ALMA continuum observations resolve a dust disk out to approximately 56 au from the star (assuming a distance of 116 pc) with 0."38 resolution and 0.07 mJy beam−1 sensitivity. We measure a continuum flux density for this inner material of 3.8±0.4 mJy (including calibration uncertainties). The 12CO(3-2) gas is resolved kinematically and spatially from about 30 to 210 au. The integrated 12CO(3-2) line flux density is 15.7±1.6 Jy km s−1. We estimate the mass of the millimeter debris and 12CO(3-2) gas to be ≳0.04 M⊕ and ∼2×10−3 M⊕, respectively. If the millimeter grains are part of a collisional cascade, then we infer that the inner disk (<50 50="" 53.4="" a="" an="" and="" around="" assumptions.="" au="" be="" blockquote="" can="" centered="" clearing="" contained="" density="" depending="" discuss="" disk="" distribution="" formation.="" gas="" generation.="" has="" hd141569="" host="" i="" if="" in="" inclination="" is="" it="" km="" less="" m="" may="" mcmc="" modeling="" morphology="" objects="" of="" on="" planet="" planetesimal="" radius="" reveals="" s="" second="" sin="" size="" stages="" star="" study="" system="" than="" the="" to="" used="" we="" whether="" with="" within="">

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

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

Authors:

Flaherty et al

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.