The DESI DR1 Peculiar Velocity Survey: Mock Catalog

TL;DR

This paper presents a comprehensive set of 675 realistic mock catalogs for the DESI DR1 Peculiar Velocity Survey, enabling precise testing of cosmological models and growth rate measurements using peculiar velocities.

Contribution

It introduces the largest and most realistic mock catalogs for DESI PV DR1, matching data properties and supporting multiple methodologies for growth rate analysis.

Findings

Mock catalogs reproduce clustering and velocity properties accurately.

Used to measure the growth rate of structure with high precision.

Achieved a consensus growth rate value of $f\sigma_8 = 0.450 \pm 0.055$.

Abstract

We describe the production of the official set of mock catalogs for the Dark Energy Spectroscopic Instrument Peculiar Velocity Survey (DESI-PV) Data Release 1 (DR1). Our mock catalogs reproduce the Bright Galaxy Survey number density and clustering at low redshift $(z<0.1)$ and the DESI PV samples of Fundamental plane and Tully-Fisher distances, from which we derive peculiar velocities. We carefully match mock and data properties and we mimic measurements of distance indicators and peculiar velocities, which follow the same statistical properties as real data. Mock samples of type-Ia supernovae also complement the other two distance indicators. Our 675 available mock realizations were used consistently by our three different methodologies described in our companion papers that measure the growth rate of structure $f\sigma_8$ with DESI PV DR1. Those mocks allow us to perform precise tests of clustering models and uncertainty estimation to an unprecedented level of accuracy, and compute correlations between methodologies. The consensus value for the DESI DR1 PV growth rate measurement is $f\sigma_8 = 0.450 \pm 0.055$. This sample of mock catalogs represents the largest and most realistic set for cosmological measurements with peculiar velocities to date.