N. Phillips

Coplanar circumbinary debris discs

We present resolved Herschel images of circumbinary debris disks in the α CrB (HD 139006) and β Tri (HD13161) systems. By modelling their structure, we find that both disks are consistent with being aligned with the binary orbital planes. Though secular perturbations from the binary can bring the disk into alignment, in both cases the alignment time at the distances at which the disk is resolved is greater than the stellar age, so we conclude that the coplanarity was primordial. Neither disk can be modelled as a narrow ring, requiring extended radial distributions. To satisfy both the Herschel and mid-IR images of the α CrB disk, we construct a model that extends from 1-300AU, whose radial profile is broadly consistent with a picture whe re planetesimal collisions are excited by secular perturbations from the binary. However, this model is also consistent with stirring by other mechanisms, such as the formation of Pluto-sized objects. The β Tri disk is modelled as a disk that extends from 50-400AU. A model with depleted (rather than empty) inner regions also reproduces the observations and is consistent with binary and other stirring mechanisms. As part of the modelling process, we find that the Herschel PACS beam varies by as much as 10% at 70µm and a few % at 100µm. The 70µm variation can therefore hinder image interpretation, par ticularly for poorly resolved objects. The number of systems in which circumbinary debris disk orientations have been compared with the binary plane is now four. More systems are needed, but a picture in which disks around very close binaries (α CrB, β Tri, and HD 98800, with periods of a few weeks to a year) are aligned, and disks around wider binaries (99 Her, with a period of 50 years) are misaligned, may be emerging. This picture is qualitatively consistent with the expectation that the p rotoplanetary disks from which the debris emerged are more likely to be aligned if their binaries have shorter periods.

Target selection for the SUNS and DEBRIS surveys for debris discs in the solar neighbourhood

Debris discs – analogous to the asteroid and Kuiper–Edgeworth belts in the Solar system – have so far mostly been identified and studied in thermal emission shortward of 100 μm. The Herschel space observatory and the Submillimetre Common-User Bolometer Array-2 (SCUBA-2) camera on the James Clerk Maxwell Telescope will allow efficient photometric surveying at 70 to 850 μm, which allows for the detection of cooler discs not yet discovered, and the measurement of disc masses and temperatures when combined with shorter wavelength photometry. The SCUBA-2 Unbiased Nearby Stars survey (SUNS) and the Disc Emission via a Bias-free Reconnaissance in the Infrared/Submillimetre (DEBRIS)Herschel Open Time Key Project are complementary legacy surveys observing samples of ∼500 nearby stellar systems. To maximize the legacy value of these surveys, great care has gone into the target selection process. This paper describes the target selection process and presents the target lists of these two surveys.

SONS: The JCMT legacy survey of debris discs in the submillimetre

During the period of these observations the James Clerk Maxwell Telescope was operated by the Joint Astronomy Centre on behalf of the Science and Technology Facilities Council of the United Kingdom, the National Research Council of Canada and the Netherlands Organisation for Pure Research. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation. MCW acknowledges the support of the European Union through ERC grant number 279973. GMK is supported by the Royal Society as a Royal Society University Research Fellow. MB acknowledges support from a FONDECYT Postdoctoral Fellowship, project no. 3140479 and the Deutsche Forschungsgemeinschaft through project Kr 2164/15-1. JPM is supported by a UNSW Vice Chancellor’s postdoctoral research fellowship. The work of OP is supported by the Royal Society through a Royal Society Dorothy Hodgkin fellowship. GJW gratefully acknowledges support from the Leverhulme Trust.

ALMA 1.3 mm Map of the HD 95086 System

Planets and minor bodies such as asteroids, Kuiper-belt objects and comets are integral components of a planetary system. Interactions among them leave clues about the formation process of a planetary system. The signature of such interactions is most prominent through observations of its debris disk at millimeter wavelengths where emission is dominated by the population of large grains that stay close to their parent bodies. Here we present ALMA 1.3 mm observations of HD 95086, a young early-type star that hosts a directly imaged giant planet b and a massive debris disk with both asteroid- and Kuiper-belt analogs. The location of the Kuiper-belt analog is resolved for the first time. The system can be depicted as a broad (

ALMA array element astronomical verification

\Delta R/R \sim

ALMA band 10 (787-950 GHz) first astronomical fringes

0.84), inclined (30\arcdeg

Analysis of antenna position measurements and weather station network data during the ALMA long baseline campaign of 2015

\pm

An unbiased study of debris discs around A-type stars with Herschel

3\arcdeg) ring with millimeter emission peaked at 200

GAS in Protoplanetary Systems (GASPS)

\pm

Debris Disks: An Unbiased Nearby A Star Sample

6 au from the star. The 1.3 mm disk emission is consistent with a broad disk with sharp boundaries from 106