Panchromatic Analysis of a Circumstellar Disk: The HV Tau C Edge-on Disk


First Author:
Gaspard Duchêne
Email: gduchene AT astro.berkeley.edu
University of California Berkeley
Astronomy Dept - 601 Campbell Hall
Berkeley CA 94705 USA
Coauthors:
Pinte, Christophe, University of Exeter
McCabe, Caer-Eve, Infrared Processing and Analysis Center
Stapelfeldt, Karl, Jet Propulsion Laboratory
Menard, Francois, Laboratoire d'Astrophysique de Grenoble
Duvert, Gilles, Laboratoire d'Astrophysique de Grenoble
Bouy, Herve, Instituto de Astrofisica de Canarias
Barrado y Navascues, David, Laboratorio de Astrofisica Espacial y Fisica Fundamental
Manness, Holly, University of California Berkeley
Padgett, Deborah, Spitzer Science Center

Abstract

Circumstellar disks can be studied through a variety of observations that includes their broadband SED, mid-infrared spectroscopy, millimeter thermal emission maps, and scattered light images. These approaches all probe different dust populations and separate regions of the disk, and it is impossible to uniquely determine all disk properties using a single observation. Instead, it is critical to combine all datasets in a consistent analysis to obtain stringent constraints on the structure and content of protoplanetary disks. Optically thick edge-on disks offer a great opportunity to easily obtain high resolution images but they also represent a major challenge in the mid-infrared regime, where they are extremely faint. The exquisitely sensitive Spitzer Space Telescope now provides a dense and continuous coverage of the SED of edge-on disks throughout the critical dip of their characteristic ``double hump'' SED, a key factor in constraining grain growth in disks. In this contribution, I will discuss the particular case of the nearly edge-on disk surrounding HV Tau C, a low-mass T Tauri star for which the available dataset is among the most complete to date, with special emphasis on data from all three Spitzer instruments. Using a single model, we simultaneously fit for the disk's optical-through-millimeter SED, scattered light images over almost a decade in wavelengths and resolved millimeter emission maps. The breadth of the considered dataset allows us to both tightly constraints some of the key parameters of the models and highlight the danger in extrapolating disk properties from a single type of observations. Applying this multi-technique, panchromatic approach to a large set of circumstellar disks will ultimately allow us to test specific predictions regarding disk evolution, such as the typical timescale for dust settling and grain growth, for instance.
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