Conclusions: The visibility data are reproduced well when thermal emission and scattering from dust are fully considered. The inner radii measured are consistent with the expected dust sublimation radii. The modelling of AK Sco suggests a likely coplanarity between the disk and the binary's orbital plane. [less ▲]Detailed reference viewed: 25 (3 ULg) CO Gas Inside the Protoplanetary Disk Cavity in HD 142527: Disk Structure from ALMAPerez, S.; Casassus, S.; Ménard, F. et alin Astrophysical Journal (2014), 798Inner cavities and annular gaps in circumstellar disks are possible signposts of giant planet formation. The young star HD 142527 hosts a massive protoplanetary disk with a large cavity that extends up to ... [more ▼]Inner cavities and annular gaps in circumstellar disks are possible signposts of giant planet formation. The young star HD 142527 hosts a massive protoplanetary disk with a large cavity that extends up to 140 AU from the central star, as seen in continuum images at infrared and millimeter wavelengths. Estimates of the survival of gas inside disk cavities are needed to discriminate between clearing scenarios. We present a spatially and spectrally resolved carbon monoxide isotopologue 2-1 line of $^12$CO, $^13$CO, and C[SUP]18[/SUP]$O obtained with the Atacama Large Millimeter/submillimeter Array (ALMA). We detect emission coming from inside the dust-depleted cavity in all three isotopologues. Based on our analysis of the gas in the dust cavity, the$^12$CO emission is optically thick, while$^13$CO and C[SUP]18[/SUP]$O emissions are both optically thin. The total mass of residual gas inside the cavity is \~1.5-2 M $_Jup$. We model the gas with an axisymmetric disk model. Our best-fit model shows that the cavity radius is much smaller in CO than it is in millimeter continuum and scattered light observations, with a gas cavity that does not extend beyond 105 AU (at 3$\sigma$). The gap wall at its outer edge is diffuse and smooth in the gas distribution, while in dust continuum it is manifestly sharper. The inclination angle, as estimated from the high velocity channel maps is 28 \plusmn 0.5 deg, higher than in previous estimates, assuming a fix central star mass of 2.2 M $_&sun;$. [less ▲]Detailed reference viewed: 27 (1 ULg) The VLTi/PIONIER survey of southern TTauri disksAnthonioz, F.; Ménard, F.; Pinte, C. et alin Booth, Mark; Matthews, Brenda; Graham, James (Eds.) Exploring the Formation and Evolution of Planetary Systems (2014, January 01)Studying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are ... [more ▼]Studying the inner regions of protoplanetary disks (1-10 AU) is of importance to understand the formation of planets and the accretion process feeding the forming central star. Herbig AeBe stars are bright enough to be routinely observed by Near IR interferometers. The data for the fainter T Tauri stars is much more sparse. In this contribution we present the results of our ongoing survey at the VLTI. We used the PIONIER combiner that allows the simultaneous use of 4 telescopes, yielding 6 baselines and 3 independent closure phases at once. PIONIER's integrated optics technology makes it a sensitive instrument. We have observed 22 T Tauri stars so far, the largest survey for T Tauri stars to this date. Our results demonstrate the very significant contribution of an extended component to the interferometric signal. The extended component is different from source to source and the data, with several baselines, offer a way to improve our knowledge of the disk geometry and/or composition. These results validate an earlier study by Pinte et al. 2008 and show that the dust inner radii of T Tauri disks now appear to be in better agreement with the expected position of the dust sublimation radius, contrary to previous claims. [less ▲]Detailed reference viewed: 33 (0 ULg) Spatially Resolved HCN J = 4-3 and CS J = 7-6 Emission from the Disk around HD 142527van der Plas, G.; Casassus, S.; Ménard, F. et alin Astrophysical Journal Letters (2014), 792The disk around HD 142527 attracts a great amount of attention compared to others because of its resolved (sub-)millimeter dust continuum that is concentrated into the shape of a horseshoe toward the ... [more ▼]The disk around HD 142527 attracts a great amount of attention compared to others because of its resolved (sub-)millimeter dust continuum that is concentrated into the shape of a horseshoe toward the north of the star. In this Letter we present spatially resolved ALMA detections of 4-3 and CS J = 7-6 emission lines. These lines give us a deeper view into the disk compared to the (optically thicker) CO 7-6 coming from a protoplanetary disk. Both emission lines are azimuthally asymmetric and are suppressed under the horseshoe-shaped continuum emission peak. A possible mechanism for explaining the decrease under the horseshoe-shaped continuum is the increased opacity coming from the higher dust concentration at the continuum peak. Lower dust and/or gas temperatures and an optically thick radio-continuum reduce line emission by freezing out and shielding emission from the far side of the disk. [less ▲]Detailed reference viewed: 30 (0 ULg) PIONIER: a 4-telescope visitor instrument at VLTILe Bouquin, J.-B.; Berger, J.-P.; Lazareff, B. et alin Astronomy and Astrophysics (2011), 535Context. PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or four 8m Unit Telescopes of the Very Large Telescope Interferometer ... [more ▼]Context. PIONIER stands for Precision Integrated-Optics Near-infrared Imaging ExpeRiment. It combines four 1.8m Auxilliary Telescopes or four 8m Unit Telescopes of the Very Large Telescope Interferometer (ESO, Chile) using an integrated optics combiner. The instrument was integrated at IPAG in December 2009 and commissioned at the Paranal Observatory in October 2010. It has provided scientific observations since November 2010.