The influence of environmental effects on Type Ia Supernovae Standardization

TL;DR

This paper investigates how the environment, specifically host galaxy morphology, influences the standardization of Type Ia Supernovae and emphasizes the importance of correcting for these effects to improve cosmological measurements.

Contribution

It demonstrates the impact of host galaxy type on supernova standardization parameters and highlights the necessity of including environmental corrections in cosmological analyses.

Findings

SNe Ia in early-type galaxies have different standardization parameters than those in late-type galaxies.

Correcting for host galaxy morphology improves the accuracy of supernova-based cosmological measurements.

Reproduced the Hubble diagram fit for the Pantheon sample with environmental considerations.

Abstract

Type Ia Supernovae (SNe Ia) are used as reliable cosmic distance indicators and their standardization is necessary for a more accurate measurement of the cosmological parameters of the Universe. However, the Hubble diagram still shows some intrinsic dispersion, potentially influenced by the supernova's environment. In this study, we reproduce the Hubble diagram fit for the Pantheon supernova sample, and also investigate the possibility of introducing various standardization equations for supernovae exploded in early- and late-type galaxies. We analyze 330 Pantheon SNe Ia to study how host galaxy morphology affects their standardization. We find that SNe Ia hosted by early-type galaxies have different standardization parameters compared to those hosted by late-type galaxies. We conclude that correcting supernova luminosity for host galaxy morphology is essential to perform the precise cosmological analysis.