| Type |
Journal Article |
| Names |
R. Dong, R. Rafikov, Z. Zhu, L. Hartmann, B. Whitney, T. Brandt, T. Muto, J. Hashimoto, C. Grady, K. Follette, M. Kuzuhara, R. Tanii, Y. Itoh, C. Thalmann, J. Wisniewski, S. Mayama, M. Janson, L. Abe, W. Brandner, J. Carson, S. Egner, M. Feldt, M. Go |
| Publication |
The Astrophysical Journal |
| Volume |
750 |
| Issue |
2 |
| Pages |
161 |
| Date |
May 1, 2012 |
| Short Title |
The Missing Cavities in the SEEDS Polarized Scattered Light Images of Transitional Protoplanetary Disks |
| URL |
http://adsabs.harvard.edu/abs/2012ApJ...750..161D |
| Library Catalog |
NASA ADS |
| Abstract |
Transitional circumstellar disks around young stellar objects have a
distinctive infrared deficit around 10 μm in their spectral energy
distributions, recently measured by the Spitzer Infrared Spectrograph
(IRS), suggesting dust depletion in the inner regions. These disks have
been confirmed to have giant central cavities by imaging of the
submillimeter continuum emission using the Submillimeter Array (SMA).
However, the polarized near-infrared scattered light images for most
objects in a systematic IRS/SMA cross sample, obtained by HiCIAO on the
Subaru telescope, show no evidence for the cavity, in clear contrast
with SMA and Spitzer observations. Radiative transfer modeling indicates
that many of these scattered light images are consistent with a smooth
spatial distribution for μm-sized grains, with little discontinuity
in the surface density of the μm-sized grains at the cavity edge.
Here we present a generic disk model that can simultaneously account for
the general features in IRS, SMA, and Subaru observations. Particularly,
the scattered light images for this model are computed, which agree with
the general trend seen in Subaru data. Decoupling between the spatial
distributions of the μm-sized dust and mm-sized dust inside the
cavity is suggested by the model, which, if confirmed, necessitates a
mechanism, such as dust filtration, for differentiating the small and
big dust in the cavity clearing process. Our model also suggests an
inwardly increasing gas-to-dust ratio in the inner disk, and different
spatial distributions for the small dust inside and outside the cavity,
echoing the predictions in grain coagulation and growth models. |
| Tags |
RADIATIVE TRANSFER, circumstellar matter, protoplanetary disks, stars: pre-main sequence |