Presentation #104.11 in the session Type Ia Supernovae — iPoster Session.
The Zwicky Transient Facility (ZTF) conducts a wide survey of the sky on a 2-3 day cadence that has produced a large, highly complete catalogue of supernovae (SNe). The Bright Transient Survey (BTS) aims to spectroscopically classify all extragalactic transients brighter than 18.5 magnitude that occur within ZTF’s 14000 square degree active footprint. The sample contains more than 6000 spectroscopically-classified SNe, making it essential to analyse the light curves in a thorough and efficient manner. We present forced photometry for all BTS transients to date, as well as detailed light curve analysis and parameter measurements extracted using Gaussian Process Regression (GPR) model fitting — a non-parametric, stochastic modelling technique that is based on a gaussian distribution over functions rather than a distribution over parameters — enabling more precise measurement of light curve parameters such as rise times, fade times and colour evolution. Two example applications of the catalogue are presented: an exploration of photometric subtypes of Type II SNe (including whether IIP and IIL subtypes represent genuinely distinct groups), and an updated study of the volumetric rates of nearly all core-collapse subtypes.