Formation of eccentric gas discs from sublimating or partially disrupted asteroids orbiting white dwarfs

Of the 21 known gaseous debris discs around white dwarfs, a large fraction of them display observational features that are well described by an eccentric distribution gas. In absence embedded objects or additional forces, these should not remain for long timescales, and instead circularise due to viscous spreading. The metal pollution infrared excess we observe from stars is consistent with presence tidally disrupted sub-stellar bodies. We demonstrate, using smoothed particle hydrodynamics, sublimating partially disrupting planet on orbit dwarf will form maintain gas disc eccentricity within 0.1 of, lower than, orbiting body. also demonstrate observed SDSS J1228+1040 can be explained same hypothesis.