Formation of sharp eccentric rings in debris disks with gas but without planets (original) (raw)

show a variety of non-trivial structures attributed to planetary perturbations and used to constrain the properties of the planets 1-3 . However, these analyses have largely ignored the fact that some debris disks are found to contain small quantities of gas 4-9 , a component that all such disks should contain at some level 10, 11 . Several debris disks have been measured with a dust-to-gas ratio around unity 4-9 at which the effect of hydrodynamics on the structure of the disk cannot be ignored 12, 13 . Here we report linear and nonlinear modelling that shows that dust-gas interactions can produce some of 1 arXiv:1307.5916v2 [astro-ph.EP] 2 Aug 2013 the key patterns attributed to planets. We find a robust clumping instability that organizes the dust into narrow, eccentric rings, similar to the Fomalhaut debris disk 14 . The conclusion that such disks might contain planets is not necessarily required to explain these systems.