C. Pinte

Unveiling the gas-and-dust disk structure in HD 163296 using ALMA observations

Aims. The aim of this work is to study the structure of the protoplan etary disk surrounding the Herbig Ae star HD 163296. Methods. We have used high-resolution and high-sensitivity ALMA observations of the CO(3‐2) emission line and the continuum at 850µm, as well as the 3- dimensional radiative transfer code MCFOST to model the data presented in this work. Results. The CO(3‐2) emission unveils for the first time at sub-millim eter frequencies the vertical structure details of a gaseou s disk in Keplerian rotation, showing the back- and the front-side of a flared disk. Continuum emission at 850 µm reveals a compact dust disk with a 240 AU outer radius and a surface brightness profil e that shows a very steep decline at radius larger than 125 AU. The gaseous disk is more than two times larger than the dust disk, with a similar critical radius but with a shallower radial pr ofile. Radiative transfer models of the continuum data confirms the need for a s harp outer edge to the dust disk. The models for the CO(3‐2) channel map require the disk to be slightly more geometrically thick than previous models suggested, and that the temperature at which CO gas becomes depleted (frozen-out) from the outer regions of the disk midplane is T < 20 K, in agreement with previous studies.

An icy Kuiper belt around the young solar-type star HD 181327

Context. HD 181327 is a young main sequence F5/F6 V star belonging to the beta Pictoris moving group (age similar to 12 Myr). It harbors an optically thin belt of circumstellar material at radius similar to 90 AU, presumed to result from collisions in a population of unseen planetesimals. Aims. We aim to study the dust properties in the belt in details, and to constrain the gas-to-dust ratio. Methods. We obtained far-infrared photometric observations of HD 181327 with the PACS instrument onboard the Herschel Space Observatory(star), complemented by new 3.2 mm observations carried with the ATCA(star star) array. The geometry of the belt is constrained with newly reduced HST/NICMOS scattered light images that allow the degeneracy between the disk geometry and the dust properties to be broken. We then use the radiative transfer code GRATER to compute a large grid of models, and we identify the grain models that best reproduce the spectral energy distribution (SED) through a Bayesian analysis. We attempt to detect the oxygen and ionized carbon fine-structure lines with Herschel/PACS spectroscopy, providing observables to our photochemical code ProDiMo. Results. The HST observations confirm that the dust is confined in a narrow belt. The continuum is detected with Herschel/PACS completing nicely the SED in the far-infrared. The disk is marginally resolved with both PACS and ATCA. A medium integration of the gas spectral lines only provides upper limits on the [OI] and [CII] line fluxes. We show that the HD 181327 dust disk consists of micron-sized grains of porous amorphous silicates and carbonaceous material surrounded by an important layer of ice, for a total dust mass of similar to 0.05 M-circle plus. (in grains up to 1 mm). We discuss evidences that the grains consists of fluffy aggregates. The upper limits on the gas atomic lines do not provide unambiguous constraints: only if the PAH abundance is high, the gas mass must be lower than similar to 17 M-circle plus. Conclusions. Despite the weak constraints on the gas disk, the age of HD 181327 and the properties of the dust disk suggest that it has passed the stage of gaseous planets formation. The dust reveals a population of icy planetesimals, similar to the primitive Edgeworth-Kuiper belt, that may be a source for the future delivery of water and volatiles onto forming terrestrial planets.

Constraining the structure of the planet-forming region in the disk of the Herbig Be star HD 100546

Studying the physical conditions in circumstellar disks is a crucial step toward understanding planet formation. Of particular interest is the case of HD 100546, a Herbig Be star that presents a gap within the first 13 AU of its protoplanetary disk, that may originate in the dynamical interactions of a forming planet. We gathered a large amount of new interferometric data using the AMBER/VLTI instrument in the H- and K-bands to spatially resolve the warm inner disk and constrain its structure. Then, combining these measurements with photometric observations, we analyze the circumstellar environment of HD 100546 in the light of a passive disk model based on 3D Monte-Carlo radiative transfer. Finally, we use hydrodynamical simulations of gap formation by planets to predict the radial surface density profile of the disk and test the hypothesis of ongoing planet formation. The SED and the NIR interferometric data are adequately reproduced by our model. We show that the H- and K-band emissions are coming mostly from the inner edge of the internal dust disk, located near 0.24 AU from the star, i.e., at the dust sublimation radius in our model. We directly measure an inclination of

CO Gas Inside the Protoplanetary Disk Cavity in HD 142527: Disk Structure from ALMA

33^{\circ} \pm 11^{\circ}

Near-infrared imaging polarimetry of HD142527 ?;??

and a position angle of

HD 97048: a closer look at the disk

140^{\circ} \pm 16^{\circ}

A HERSCHEL SURVEY OF COLD DUST IN DISKS AROUND BROWN DWARFS AND LOW-MASS STARS*

for the inner disk. This is similar to the values found for the outer disk (

Gas modelling in the disc of HD 163296

i \simeq 42^{\circ}

Detection of warm water vapour in Taurus protoplanetary discs by Herschel

,

Sculpting the disk around T Chamaeleontis: an interferometric view

PA \simeq 145^{\circ}