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

Poster 2B014

Evidence of a discontinuous inner disk structure around the Herbig star HD 139 614

Matter, Alexis (Max Planck institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany; UJF-Grenoble 1 / CNRS INSU, Institut de Planétologie et d\'Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 )
Labadie, Lucas (I. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany)
Kreplin, Alexander (Max Planck institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany)
Lopez, Bruno (Laboratoire Lagrange, CNRS UMR 7293, UNS-Observatoire de la Côte d’Azur BP 4229, F-06304 Nice Cedex 4, France)
Wolf, Sebastian (Universität zu Kiel, Institut für Theoretische Physik und Astrophysik, Leibnizstr. 15, 24098 Kiel, Germany)
Weigelt, Gerd (Max Planck institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany)
Ertel, Steve (UJF-Grenoble 1 / CNRS INSU, Institut de Planétologie et d\'Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041)
Pott, Jörg-Uwe (Max Planck Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany)
Danchi, William C. (NASA/GSFC, Greenbelt, MD 20771, USA)

Abstract:
A new class of pre-main sequence objects has been recently identified as `pre-transitional disks\'. They present a near-infrared excess coupled to a flux deficit around 10 microns and then a rising mid-infrared spectrum. Therefore, they probably represent disk showing an inner and outer dust component separated by a dust-depleted region (or gap). Such a configuration could be for instance the result of planet formation processes occuring during the disk evolution (see e.g. the case of LkCa 15; Espaillat et al. 2008, Kraus et al. 2012). We here report on the first interferometric observations of the disk around the Herbig Ae star HD 139 614. Its infrared spectrum suggests a flared disk and presents a substantial near-infrared excess accompanied by a dip around 6 microns, then followed by a rising mid-infrared part. We modeled both the SED and mid-infrared VLTI/MIDI interferometric data to constrain the spatial structure of the inner dust disk region, and assess its possibly multi-component organisation. A good agreement with the measured mid-infrared SED and interferometric visibilities was obtained with an unresolved component emitting at 1500 K, followed by a gap extending to 5.9 AU, and an outer temperature-gradient disk characterized by a steep temperature profile and a high temperature of about 350 K at its inner edge. This suggests a warm component corresponding to the inner edge of the outer disk directly illuminated by the central star. This is an expected consequence of the presence of a gap, possibly indicative of a pre-transitional structure. However, our best-fit model underestimated the near-infrared excess. This suggests the existence of an extended inner component that is partly resolved by MIDI.

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