A revised SALT2 surface for fitting Type Ia supernova light curves

ABSTRACT We present a revised Spectral Adaptive Light Curve Template (SALT2) surface (SALT2-2021) for fitting the light curves of Type Ia supernovae (SNe Ia), which incorporates new measurements zero-point calibration offsets and Milky Way extinction. The most notable change in occurs UV region. This alters distance SNe Ia, can be used to investigate nature dark energy by probing expansion history Universe. Using SALT2 on public data from first 3 yr Dark Energy Survey Supernova Program (combined with an external low-z sample) combining cosmic microwave background constraints, we find equation-of-state parameter, ?w = 0.015 ± 0.004. result highlights continued importance controlling reducing systematic uncertainties, particularly next generation supernova analyses aiming improve constraints properties.