PISCOLA: a data-driven transient light-curve fitter

Abstract

Forthcoming time-domain surveys, such as the Rubin Observatory Legacy Survey of Space and Time, will vastly increase samples of supernovae (SNe) and other optical transients, requiring new data-driven techniques to analyse their photometric light curves. Here, we present the "Python for Intelligent Supernova-COsmology Light-curve Analysis" (PISCOLA), an open source data-driven light-curve fitter using Gaussian Processes that can estimate rest-frame light curves of transients without the need for an underlying light-curve template. We test PISCOLA on large-scale simulations of type Ia SNe (SNe Ia) to validate its performance, and show it successfully retrieves rest-frame peak magnitudes for average survey cadences of up to 7 days. We also compare to the existing SN Ia light-curve fitter SALT2 on real data, and find only small (but significant) disagreements for different light-curve parameters. As a proof-of-concept of an application of PISCOLA, we decomposed and analysed the PISCOLA rest-frame light-curves of SNe Ia from the Pantheon SN Ia sample with Non-Negative Matrix Factorization. Our new parametrization provides a similar performance to existing light-curve fitters such as SALT2. We further derived a SN Ia colour law from PISCOLA fits over $\sim$3500 to 7000Å, and find agreement with the SALT2 colour law and with reddening laws with total-to-selective extinction ratio $R_V\lesssim 3.1$.

Accepted in MNRAS

References in corpus (14)

• Array Programming with NumPy
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Supernova Constraints and Systematic Uncertainties from the First 3 Years of the Supernova Legacy Survey
• Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
• CfA3: 185 Type Ia Supernova Light Curves from the CfA
• Determining the Type, Redshift, and Age of a Supernova Spectrum
• The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary
• SiFTO: An Empirical Method for Fitting SNe Ia Light Curves
• The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae
• The Rise and Fall of Type Ia Supernova Light Curves in the SDSS-II Supernova Survey
• The Host Galaxies of Rapidly Evolving Transients in the Dark Energy Survey
• SN 2016jhj at redshift 0.34: extending the Type II supernova Hubble diagram using the standard candle method
• SuperNova IDentification spectral templates of 70 stripped-envelope core-collapse supernovae