Oral Presentation

The Worlds in Collision in Debris Disks of Low Mass Stars

Author(s): Wing Ip

Presenter: Wing Ip (Institutes of Astronomy and Space Science, National Central University)

The standard model of solar system formation and architecture indicates that the initial process of planetary accretion should be concluded by an episode of large-scale gravitational scattering of the planetoids and planetesimals by protoplanets leading to intense impact collisions of the small bodies and heavy bombardment of the planetary surfaces. Recent observations in MIR and FIR by ground-based and space-born telescopes have found interesting evidence for gas-rich/dust-rich debris disks that might be related to collisional effects of sizable objects in the circumstellar disks. It can be envisaged that the protoplanetary systems of low-mass stars of different spectral types would be characterized by the presence of Kuiper belt analogues in the outer regions and time-variable early scattering/impact process in the inner regions. A number of observations and plausible scenarios are illustrated in this report. It is most desirable that the proposed SPICA mission will be able to provide comprehensive observations of unprecedented sensitivity to decipher the histories of the formation and dynamical evolution of exoplanets in their debris disks, as depicted.