The Peak Luminosity–Decline Rate Relationship for Type Ia Supernovae

A Linear Relation Between the Color Stretch $s_{BV}$ and the Rising Color Slope $s_0^*(B-V)$ of Type Ia Supernovae

“…As a supernova (SN) population, SNe Ia show remarkable regularities in observed properties, and in particular, their light curves follow a tight relation between peak luminosity and the decline rate, which is commonly referred to as the width-luminosity relation (WLR, see Phillips & Burns 2017 for a review). The empirical WLR extends from the most luminous 1991T-like SNe Ia (Filippenko et al 1992a;Ruiz-Lapuente et al 1992;Phillips et al 1992) to the least luminous 1991bg-like SNe Ia (Filippenko et al 1992b;Leibundgut et al 1993;Turatto et al 1996).…”

“…For low-luminosity, fast-declining SNe Ia, ∆m 15 (B) is found to be a poor width discriminator, and the WLR using ∆m 15 (B) shows a large scatter for ∆m 15 (B) 1.7 mag (see, e.g., Burns et al 2014;Gall et al 2018). Similarly, the stretch method fails for fast decliners (see, e.g., Phillips & Burns 2017). From studying highquality B − V color curves of SNe Ia observed by the Carnegie Supernova Project (CSP), Burns et al (2014) found that fast-declining SNe Ia reach their reddest B − V color earlier than those with slower decline rates.…”

Evolution of fission-ignited supernova properties with uranium enrichment

“…Type-Ia supernovae (SN Ia) are great stellar explosions that provide important distance indicators in cosmology Abbott et al (2019); Howell (2011); Sullivan (2010). They can be observed at great distances and appear to have a standardizable luminosity that can be inferred from other observations Riess et al (1996); Phillips et al (1999); Goldhaber et al (2001); Phillips & Burns (2017); Hayden et al (2019). This allows a precise determination of the expansion rate of the universe known as the Hubble constant.…”

Type Ia Supernova Cosmology

“…More detailed observations have led to sophisticated treatments and standardisations, involving light curves, spectra, and the star-formation rate and stellar masses of the SN Ia host galaxies. The light-curve shape vs. luminosity relation as originally introduced by Phillips (1993) was the most important improvement to achieve distance accuracies required to detect the acceleration and to bring the uncertainty in the determination of H 0 to less than 5% (see Phillips and Burns 2016, for a review on the different light curve correction methods). Today, the most popular correction methods are SALT2 (Guy et al 2007), MLCS2k2 (Jha et al 2007), SNooPy (Burns et al 2011) and SiFTO (Conley et al 2008).…”