Details

Autor(en) / Beteiligte

• Honda, M
• Inoue, A. K
• Okamoto, Y. K
• Kataza, H
• Fukagawa, M
• Yamashita, T
• Fujiyoshi, T
• Tamura, M
• Hashimoto, J
• Miyata, T
• Sako, S
• Sakon, I
• Fujiwara, H
• Kamizuka, T
• Onaka, T

Titel

Pre-transitional Disk Nature of the AB Aur Disk

Ist Teil von

• Astrophysical journal. Letters, 2010-08, Vol.718 (2), p.L199-L203

Ort / Verlag

United States: IOP Publishing

Erscheinungsjahr

2010

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The disk around AB Aur was imaged and resolved at 24.6 {mu}m using the Cooled Mid-infrared Camera and Spectrometer on the 8.2 m Subaru Telescope. The Gaussian full width at half-maximum of the source size is estimated to be 90 {+-} 6 AU, indicating that the disk extends further out at 24.6 {mu}m than at shorter wavelengths. In order to interpret the extended 24.6 {mu}m image, we consider a disk with a reduced surface density within a boundary radius R{sub c} , which is motivated by radio observations that suggest a reduced inner region within about 100 AU from the star. Introducing the surface density reduction factor f{sub c} for the inner disk, we determine that the best match with the observed radial intensity profile at 24.6 {mu}m is achieved with R{sub c} = 88 AU and f{sub c} = 0.01. We suggest that the extended emission at 24.6 {mu}m is due to the enhanced emission from a wall-like structure at the boundary radius (the inner edge of the outer disk), which is caused by a jump in the surface density at R{sub c} . Such a reduced inner disk and geometrically thick outer disk structure can also explain the more point-like nature at shorter wavelengths. We also note that this disk geometry is qualitatively similar to a pre-transitional disk, suggesting that the AB Aur disk is in a pre-transitional disk phase.