Reconstruction with velocities

TL;DR

This paper explores using radial velocities from the kinematic Sunyaev-Zel'dovich effect to improve galaxy reconstruction near survey boundaries, significantly reducing boundary effects in clustering analysis.

Contribution

It introduces a novel approach of incorporating velocity data from CMB observations to mitigate boundary effects in galaxy reconstruction.

Findings

Velocity information reduces boundary effects from ~100 Mpc/h to ~30-40 Mpc/h.

Using Simons Observatory data enhances reconstruction accuracy near survey edges.

Method benefits dense, low-redshift galaxy surveys with limited volume.

Abstract

Reconstruction is becoming a crucial procedure of galaxy clustering analysis for future spectroscopic redshift surveys to obtain subpercent level measurement of the baryon acoustic oscillation scale. Most reconstruction algorithms rely on an estimation of the displacement field from the observed galaxy distribution. However, the displacement reconstruction degrades near the survey boundary due to incomplete data and the boundary effects extend to $\sim100\,\mathrm{Mpc}/h$ within the interior of the survey volume. We study the possibility of using radial velocities measured from the cosmic microwave background observation through the kinematic Sunyaev-Zel'dovich effect to improve performance near the boundary. We find that the boundary effect can be reduced to $\sim30-40\,\mathrm{Mpc}/h$ with the velocity information from Simons Observatory. This is especially helpful for dense low redshift surveys where the volume is relatively small and a large fraction of total volume is affected by the boundary.