The redshift distribution of cosmological samples: a forward modeling approach

Understand

Determining the redshift distribution $n(z)$ of galaxy samples is essential for several cosmological probes including weak lensing.

• For imaging surveys, this is usually done using photometric redshifts estimated on an object-by-object basis.
• We present a new approach for directly measuring the global $n(z)$ of cosmological galaxy samples, including uncertainties, using forward modeling.
• Our method relies on image simulations produced using UFig (Ultra Fast Image Generator) and on ABC (Approximate Bayesian Computation) within the $MCCL$ (Monte-Carlo Control Loops) framework.