Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 2B051

Resolving the gap and AU-scale asymmetries in pre-transitional disks with multi-wavelength interferometry

Kraus, Stefan (University of Exeter)
Ireland, Michael (Macquarie University)
Sitko, Michael (University of Cincinnati)
Monnier, John (University of Michigan)
Calvet, Nuria (University of Michigan)
Espaillat, Catherine (Harvard-Smithsonian Center for Astrophysics)
Grady, Carol (Eureka Scientific Inc. and Goddard Space Flight Center)
Harries, Tim (University of Exeter)
Hoenig, Sebastian (University of California Santa Barbara)
Russell, Ray (The Aerospace Corporation, Visiting Scientist NASA IRTF)
Kim, Daryl (The Aerospace Corporation, Visiting Scientist NASA IRTF)
Swearing, Jeremy (University of Cincinnati)
Werren, Chelsea (University of Cincinnati)
Wilner, David (Harvard-Smithsonian Center for Astrophysics)

Pre-transitional disks are protoplanetary disks with a gapped disk structure, potentially indicating the presence of young planets in these systems. In this contribution, we present near- and mid-infrared interferometric observations, which allow us to explore the structure of these objects and their gap-opening mechanism. For instance, our observations on V1247 Orionis employ the VLT Interferometer, the Keck Interferometer, Keck-II, Gemini South, and IRTF, and reveal a narrow, optically-thick inner-disk component (located at 0.20 AU from the star) that is separated from the optically thick outer disk (radii >= 49 AU), providing unambiguous evidence for the existence of a gap in this pre-transitional disk. Surprisingly, we find that the gap region is filled with significant amounts of optically thin material with a carbon-dominated dust mineralogy. The presence of this optically thin gap material cannot be deduce solely from the spectral energy distribution, yet it is the dominant contributor at mid-infrared wavelengths. Furthermore, using Keck/NIRC2 aperture masking observations in the H, K\', and L\'-band, we detect asymmetries in the brightness distribution on scales of 15-45 AU, i.e. within the gap region. The detected asymmetries are highly significant, yet their amplitude and direction changes with wavelength, which is not consistent with a companion interpretation but indicates an inhomogeneous distribution of the gap material. We interpret this as strong evidence for the presence of complex density structures, possibly reflecting the dynamical interaction of the disk material with sub-stellar mass bodies that are responsible for the gap clearing.

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