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Activity > Lunch Talk

Lunch Talk (2023)

ASIAA Lunch Talk is an institute-wide event allowing ASIAA researchers from different fields to discuss astronomy in a very casual manner. The informal meeting is usually held at lunch time on every Monday. Occasionally visitors are also invited to the lunch talk to share their research and ideas with ASIAA researchers.

    Contact
  • Lunch Talk: Colloquium Committee (talks_replace2@_asiaa.sinica.edu.tw)
  • Tech Lunch Talk: Chang, Hsiao-Wen (hwchang_replace2@_asiaa.sinica.edu.tw)
NEXT Lunch Talk: 2023-02-13 Mon 12:00~12:40 [R1203]
Speaker:Sheng-Jun Lin
No. Time/Place Speaker Topic (Abstract)
download PDF: dowaload talk PDF file
12023-04-24 Mon
12:00~12:40
R1412
Sujin Eie
[ASIAA]
22023-04-17 Mon
12:00~12:40
R1203
Konstantin Gerbig
[Yale]
32023-04-10 Mon
12:00~12:40
R1412
Bangwon Lee
[ASIAA]
42023-03-27 Mon
12:00~12:40
R1412
Indrani Das
[ASIAA]
52023-03-20 Mon
12:00~12:40
R1412
Mayank Narang
[ASIAA]
62023-03-13 Mon
12:00~12:40
R1412
Howard Chen
[Florida Tech]
72023-03-06 Mon
12:00~12:40
R1412
Masayuki Yamaguchi
[ASIAA]
82023-02-20 Mon
12:00~12:40
R1412
Kiyoaki Doi
[NAOJ]
Constraining the dust size distribution in the protoplanetary disk around HD 163296 from the observed wavelength dependency of the dust ring width
Abstract

Planet formation begins with the coagulation of dust grains in protoplanetary disks. Therefore, constraints on the dust size distribution in the disks can provide a clue to understanding planet formation. Previous studies have estimated the dust size distribution using the spectral index derived from multi-wavelength observations or dust polarization observations. However, these studies give different results depending on their methods and model assumptions and do not reach a consensus. In this work, we propose another indirect method to constrain the dust size distribution by using the wavelength dependency of the dust ring widths. In many disks, there are dust and gas rings, and larger dust grains are more effectively trapped in the gas rings, forming narrower dust rings. As a result, the dust rings are expected to appear narrower at longer wavelengths since the observations are sensitive to the dust grains whose size is comparable to the observed wavelength. We analyze high-resolution Band 4 (2.1 mm) and Band 6 (1.3 mm) images of the HD 163296 disk. We find for the first time that the width of the outer dust ring (100 au) appears 1.2 times narrower at the longer wavelength, while the width of the inner ring (67 au) is similar between the two bands. The difference in the ring width depending on the observed wavelength is consistent with the dust trapping scenario in a gas ring. We constrain the maximum dust size a_max and the exponent of the dust size distribution p from the difference in dust ring width between the two bands, together with the spectral index, and found that 1 mm < a_max < 20 mm and p < 3.5 in the inner ring, and a_max > 30 mm and 3.4 < p < 3.6 in the outer ring. These results suggest that the degree of dust growth is spatially dependent, which could affect the formation of planetesimals.

92023-02-13 Mon
12:00~12:40
R1203
Sheng-Jun Lin
[ASIAA]
102023-01-09 Mon
12:00~12:40
R1412
Chi-Ting Chiang
[Susquehanna International Group]
Career series: from cosmology to finance
TEL: 886-2-3365-2200 FAX: 886-2-2367-7849
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