Mock galaxy catalogues using the quick particle mesh method

Sophisticated analysis of modern large-scale structure surveys requires mock catalogues. Mock catalogues are used to optimize survey design, test reduction and analysis pipelines, make theoretical predictions for basic observables and propagate errors through complex analysis chains. We present a new method, which we call 'quick particle mesh', for generating many large volume, approximate mock catalogues at low computational cost. The method is based on using rapid, low-resolution particle mesh simulations that accurately reproduce the large-scale dark matter density field. Particles are sampled from the density field based on their local density such that they have N-point statistics nearly equivalent to the haloes resolved in high-resolution simulations, creating a set of mock haloes that can be populated using halo occupation methods to create galaxy mocks for a variety of possible target classes.