ES-01-0001

Can an exo-Oort cloud pollute white dwarfs?

Cao Dang Pham

Strong metal absorption lines are found in the spectra of 25-50% of white dwarfs atmospheres. These elements are expected to sink quickly, pointing to a scenario of materials accretion delivered from elsewhere in these evolved exoplanetary systems. In addition, the inferred accretion rate is found to be roughly constant, decreasing by only about one order of magnitude, over the course of 8 Gigayears. A potential reservoir for these materials would be an Oort cloud analog. Here, we are contributing to prior work on white dwarf pollution via an Oort cloud by finding the flux rate of comets experiencing the following perturbations: galactic tides, stellar flyby, white dwarf natal kick and an interior planet. We use lessons from studying our own Solar System’s Oort cloud perturbations via galactic tides and stellar perturbations, approximating the white dwarf kick as impulsive and developing a new semi-analytical technique to account for scattering by a planet.