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The Asymmetric Thermal Emission of Protoplanetary Disk Surrounding HD 142527 Seen by Subaru/COMICS

Hideaki Fujiwara·Mitsuhiko Honda·Hirokazu Kataza·Takuya Yamashita·Takashi Onaka·Misato Fukagawa·Yoshiko K. Okamoto·Takashi Miyata·Shigeyuki Sako·Takuya Fujiyoshi·Itsuki Sakon
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Abstract

Mid-infrared (MIR) images of the Herbig Ae star HD 142527 were obtained at 18.8 and 24.5 micron with the Subaru/COMICS. Bright extended arc-like emission (outer disk) is recognized at r=0.85" together with a strong central source (inner disk) and a gap around r=0.6" in the both images. Thermal emission of the eastern side is much brighter than that of the western side in the MIR. We estimate the dust size as a few micron from the observed color of the extended emission and the distance from the star. The dust temperature T and the optical depth tau of the MIR emitting dust are also derived from the two images as T=82+/-1K, tau=0.052+/-0.001 for the eastern side and T=85+/-3K, tau=0.018+/-0.001 for the western side. The observed asymmetry in the brightness can be attributed to the difference in the optical depth of the MIR emitting dust. To account for the present observations, we propose an inclined disk model, in which the outer disk is inclined along the east-west direction with the eastern side being in the far side and the inner rim of the outer disk in the eatern side is exposed directly to us. The proposed model can successfully account for the MIR observations as well as near-infrared (NIR) images of the scattering light, in which the asymmetry is seen in the opposite sense and the forward scattering light (near side -- western side) is brighter.

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Hideaki Fujiwara, Mitsuhiko Honda, Hirokazu Kataza, Takuya Yamashita, Takashi Onaka, Misato Fukagawa, Yoshiko K. Okamoto, Takashi Miyata, Shigeyuki Sako, Takuya Fujiyoshi, Itsuki Sakon. 2007-01-29. The Asymmetric Thermal Emission of Protoplanetary Disk Surrounding HD 142527 Seen by Subaru/COMICS. https://doi.org/10.1086/505597

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