Mark WYATT : IoA, University of Cambridge
Theoretical modeling of debris disc structure
Our understanding of the structure of debris discs has progressed rapidly in the last few years due to advances in our ability to image those discs; 9 out of the 15 discs with resolved structure had that structure resolved for the first time in the last year. The discs have been shown to be quite unlike the smooth axisymmetric rings one might expect for planetesimal belts evolving in quasi-steady state. Rather the discs exhibit asymmetries, clumps, offsets, warps, and spiral structure. It also appears that different grain components have different spatial distributions, as evidenced by imaging in different wavelengths. In this talk I will review the models which have been presented in the literature to explain the observed structures. Many of these invoke the presence of unseen planets which sculpt the discs through secular and resonant gravitational perturbations to the orbits of the planetesimals and dust. All models need to consider the interplay between collisions, P-R drag, and radiation pressure, as well as stellar wind forces to properly account for the physics of the discs, and in doing so most, but not all, of the observed structures can be reproduced.Last modified: Sun Jul 9 18:23:40 2006