Redshift-space implementation of percolation

Develop a redshift-space implementation of the proximity-based percolation method for outer-stellar-mass cluster selection, accounting for the effects of peculiar velocities and redshift uncertainties on line-of-sight galaxy associations.

Background

The percolation analysis is performed on projected real-space positions through the full simulation box without applying a line-of-sight selection. Consequently, some central galaxies are removed because of chance alignments with more massive galaxies separated by 4–100 Mpc along the line of sight. In observational data, peculiar velocities and redshift uncertainties would limit the precision with which galaxies can be separated in the line-of-sight direction, so applying the method to surveys requires a redshift-space formulation.

References

We note, however, that the situation in real data is more complicated: peculiar velocities and redshift uncertainties limit how finely galaxies can be separated along the line of sight, and we leave a redshift-space implementation of the percolation to future work.

— Cluster finding with outskirt stellar masses and percolation  (2608.19768 - Avalos et al., 20 Aug 2026) in Section 3, subsection “Massive Halo Selection,” paragraph discussing removed central galaxies and chance line-of-sight alignments