【場所】国立天文台・三鷹 中央棟（北）1階 講義室
【発表者１（敬称略）】片岡章雅（総研大 D1・三鷹、指導教員 : 富阪幸治)
Settling Process of Dust Aggregates in Protoplanetary disks with Porosity Evolution
abstract: How micron-sized dust aggregates evolve to kilo-meter-sized planetesimals in protoplanetary disks is one of the most important problems of the planet formation. Some previous studies using BPCA and/or BCCA models have shown that porosity has strong effects on coagulation and settling of dust aggregates. However, effects of the porosity evolution have not been taken into account before. We simulate coagulation of dust aggregates settling to an equatorial plane in a protoplanetary disk, using QBCCA model, in which the porosity evolution depends on the volume ratio of colliding two aggregates. We show that porous aggregates grow slowly and settle in longer timescale compared to compact grains. We also calculate wavelength-dependent optical depth and find that the 10 $\micron$ silicate feature remains in the case of porous aggregates even after they grow in the disk. Moreover, we find that compaction of dust aggregates affects optical depth in (sub)mm wavelength, which would be detected by ALMA.