Standardization, Distance, Host Galaxy Extinction of Type Ia Supernova and Hubble Diagram from the Flux Ratio Method

TL;DR

This paper extends the flux ratio method for Type Ia supernovae to better estimate host galaxy extinction and distances, enabling improved Hubble diagram construction and insights into cosmic acceleration.

Contribution

It generalizes the flux ratio method to include multiple luminosity indicators and applies it across different redshifts for more accurate supernova distance and extinction measurements.

Findings

Flux ratio method constrains host galaxy extinction E(B-V) effectively.

High redshift supernova distances fit well with the method, supporting cosmic acceleration.

Supports the use of flux ratios as a tool for cosmological studies.

Abstract

In this paper we generalize the flux ratio method Bailey et al. (2009) to the case of two luminosity indicators and search the optimal luminosity-flux ratio relations on a set of spectra whose phases are around not only the date of bright light but also other time. With these relations, a new method is proposed to constrain the host galaxy extinction of SN Ia and its distance. It is first applied to the low redshift supernovas and then to the high redshift ones. The results of the low redshift supernovas indicate that the flux ratio method can indeed give well constraint on the host galaxy extinction parameter E(B-V), but weaker constraints on R_{V}. The high redshift supernova spectra are processed by the same method as the low redshift ones besides some differences due to their high redshift. Among 16 high redshift supernovas, 15 are fitted very well except 03D1gt. Based on these distances, Hubble diagram is drew and the contents of the Universe are analyzed. It supports an acceleration behavior in the late Universe. Therefore, the flux ratio method can give constraints on the host galaxy extinction and supernova distance independently. We believe, through further studies, it may provide a precise tool to probe the acceleration of the Universe than before.