Heating of Dust Particles and Chondrule Formation Induced by Shock-Waves in Upper Layer of Protoplanetary Disks Generated by X-Ray Flares

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We studied the phenomen that a magnetic bubble caused by X-Ray flare of the central star generates the shock waves at the surface of protoplanetary disks around the central star. And we looked at the characteristics of shock waves to examine if they can heat dust particles in the disk enough to melt them and form chondrules based on the shock-wave heating model for chondrule formation. Especially, we focused on following three points : (1) if such an phenomen may take place, (2) if it occurs what kind of effects they may bring to materials in the disk, and (3) if we can know the presence of the phenomen by making observation astronomically and meteoritically. To approach these problems, we have conducted Magneto-Hydrodynamics (MHD) numerical simulations, radiative transfer numerical simulations, analytic investigations, and so forth.Our MHD simulations have revealed that shock waves can be formed by the magnetic bubbles associated with X-Ray flares. And some of those shock waves turned … More out to be appropriate for chondrule formation and crystallization of dust particles. Namely, (a) dust particles in the disk region closer than 3 AU from the central star can be heated enough, and (b) it is unlikely that dust particle in a region further than about 5 AU are heated by the shock waves because the bubble would not reach that region due to the collimation.On the other hand, thanks to the detailed simulations, we can now discuss places where dust particles are heated to form chondrules and/or crystallize precisely. And we can discuss the possibility that heated and crystallized dust particles may be incorporated in comets. This discussion implies that crystallized dust particles in observed comets should be transferred from the inner region of the solar system, because the shock wave heating can only take place in a region closer than 5 AU.Some possible transfer mechanisms of dust particles have been proposed so far, but we need to investigate those mechanisms in detail in the future. Less