[P-CG22] Origin and evolution of materials in space

[PCG22-01] Theoretical studies on dust aggregates and implications for uncertainty of dust properties

★Invited Papers

*Misako Tatsuuma¹, Akimasa Kataoka², Satoshi Okuzumi³, Hidekazu Tanaka⁴, Tristan Guillot⁵ (1.RIKEN, 2.NAOJ, 3.Tokyo Institute of Technology, 4.Tohoku University, 5.Côte d'Azur Observatory)

Keywords:dust aggregates, strength, collisional fragmentation velocity, surface energy, monomer radius

The first step of planet formation is the sticking of submicron-sized dust grains and the subsequent formation of dust aggregates. The physical properties of dust grains, such as stickiness and fragility, determine the behavior of aggregates and affect the size growth of dust aggregates. However, the physical properties of dust grains have large uncertainty, and material strengths and collisional fragmentation velocity are formulated by using some parameters as the physical properties in theoretical studies of dust aggregates. One of these parameters is surface energy, which represents stickiness and has large uncertainty. To reduce it, it is essential to constrain the chemical properties of the dust surface layers by using observations of protoplanetary disks. Another parameter is the size of the dust grains as monomers that form the aggregates. The monomer radius could be constrained by the information on minerals in meteorites and asteroids' return samples. In addition, the strength of monomer disruption has large uncertainty, which may also be constrained using minerals. In this talk, I will introduce theoretical studies on the material strength and collisional fragmentation velocity of dust aggregates, discuss the connections to chemistry and mineralogy as implications for the uncertainty of dust properties, and introduce related studies.