The Influence of the Peculiar Velocities of SNe Ia in Clusters of Galaxies on the Redshift Measurements

TL;DR

This paper investigates how the peculiar velocities of host galaxies in clusters affect redshift measurements of Type Ia Supernovae, proposing a method to reduce this source of uncertainty in cosmological parameter estimation.

Contribution

It introduces a procedure to minimize the impact of peculiar velocities of SNe Ia host galaxies in clusters on redshift measurements.

Findings

Peculiar velocities significantly influence redshift accuracy.

A new method effectively reduces velocity-induced uncertainties.

Improved redshift measurements enhance cosmological parameter estimates.

Abstract

The most intriguing question of modern astronomy is the question of our Universe formation. The Hubble diagram analysis with Type Ia Supernovae (SNe Ia) is widely used to estimate the cosmological parameters with high accuracy. The cosmological measurements allow us to better understand the early stages of the Universe evolution. Nevertheless, the redshift on the SN Ia Hubble diagram includes the contribution from the unknown peculiar velocities that decreases the accuracy of such measurements. We consider the contamination of peculiar velocities of the host galaxies for those SNe that exploded in galaxy clusters. For this purpose, we use the Pantheon cosmological sample and offer the procedure to minimise the influence of such uncertainties.