2017年1月

# Detailed modeling of dust distribution in the disk of HD 142527

Publications of the Astronomical Society of Japan
• Kang-Lou Soon
• ,
• Tomoyuki Hanawa
• ,
• Takayuki Muto
• ,
• Takashi Tsukagoshi
• ,
• Munetake Momose

We investigate the dust distribution in the crescent disk around HD 142527<br />
based on the continuum emission at $890 \mathrm{\ \mu m}$ obtained by ALMA<br />
Cycle 0. The map is divided into $18$ azimuthal sectors, and the radial<br />
intensity profile in each sector is reproduced with a 2D disk model. Our model<br />
takes account of scattering and inclination of the disk as well as the<br />
azimuthal dependence in intensity. When the dust is assumed to have the<br />
conventional composition and maximum size of $1\ \mathrm{mm}$, the northwestern<br />
region ($PA=329^{\circ}-29^{\circ}$) cannot be reproduced. This is because the<br />
model intensity gets insensitive to the increase in surface density due to<br />
heavy self-scattering, reaching its ceiling much lower than the observed<br />
intensity. The ceiling depends on the position angle. When the scattering<br />
opacity is reduced by a factor of $10$, the intensity distribution is<br />
reproduced successfully in all the sectors including those in the northwestern<br />
region. The best fit model parameters depend little on the scattering opacity<br />
in the southern region where the disk is optically thin. The contrast of dust<br />
surface density along $PA$ is derived to be about $40$, much smaller than the<br />
value for the cases of conventional opacities ($70-130$). These results<br />
strongly suggest that the albedo is lower than considered by some reasons at<br />
least in the northwestern region.

リンク情報
arXiv
http://arxiv.org/abs/arXiv:1701.06706
URL
http://arxiv.org/abs/1701.06706v1