1703.03407
LIGER: mock relativistic light-cones from Newtonian simulations
Borzyszkowski, Bertacca, Porciani
A new method to create mock galaxy catalogues in z space including GR to linear order in cosmo perturbations. LIGER (light cones with general relativity) takes a N-body or hydro Newtonian sim as an input and outputs the distribution of galaxies in comoving redshift space. This result is achieved making use of a coordinate transformation and simultaneously accounting for lensing magnification. The calculation includes both local corrections and terms that have been integrated along the line of sight. The fast implementation allows the production of many realizations that can be used to forecast the performance of forthcoming wide-angle surveys and to estimate the covariance matrix of the observables. To facilitate this use, also present a variant of LIGER designed for large-volume sims with low mass resolution. In this case, the galaxy distribution on large scales is obtained by biasing the matter-density field. Finally, present two sample applications of LIGER. First, discuss the impact of weak gravitational lensing onto the angular clustering of galaxies in a Euclid-like survey. In agreement with previous analytical studies, find that magnification bias can be measured with high confidence. Second, focus on two generally neglected Doppler-induced effects: magnification and the change of number counts with redshift. Show that the corresponding z-space distortions can be detected at 5.5 sigma significance with the completed SKA.
No comments:
Post a Comment