SALT3-NIR: Taking the Open-Source Type Ia Supernova Model to Longer Wavelengths for Next-Generation Cosmological Measurements

Abstract

A large fraction of Type Ia supernova (SN Ia) observations over the next decade will be in the near-infrared (NIR), at wavelengths beyond the reach of the current standard light-curve model for SN Ia cosmology, SALT3 ($\sim 2800$--8700$A$ central filter wavelength). To harness this new SN Ia sample and reduce future light-curve standardization systematic uncertainties, we train SALT3 at NIR wavelengths (SALT3-NIR) up to 2 $\mu$m with the open-source model-training software SALTShaker, which can easily accommodate future observations. Using simulated data we show that the training process constrains the NIR model to $\sim 2$--3% across the phase range ($-20$ to $50$ days). We find that Hubble residual (HR) scatter is smaller using the NIR alone or optical+NIR compared to optical alone, by up to $\sim 30$% depending on filter choice (95% confidence). There is significant correlation between NIR light-curve stretch measurements and luminosity, with stretch and color corrections often improving HR scatter by up to $\sim 20$. For SN Ia observations expected from the \textit{Roman Space Telescope}, SALT3-NIR increases the amount of usable data in the SALT framework by $\sim 20$% at redshift $z\lesssim 0.4$ and by $\sim 50$% at $z\lesssim 0.15$. The SALT3-NIR model is part of the open-source {\tt SNCosmo} and {\tt SNANA} SN Ia cosmology packages.

References in corpus (18)

• The Zwicky Transient Facility: Data Processing, Products, and Archive
• 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
• The UKIRT Wide Field Camera ZYJHK Photometric System: Calibration from 2MASS
• WMAP constraints on low redshift evolution of dark energy
• Correcting Type Ia Supernova Distances for Selection Biases and Contamination in Photometrically Identified Samples
• The Carnegie Supernova Project: Intrinsic Colors of Type Ia Supernovae
• The Carnegie Supernova Project I: Third Photometry Data Release of Low-Redshift Type Ia Supernovae and Other White Dwarf Explosions
• SN 2003du: 480 days in the Life of a Normal Type Ia Supernova
• Measuring the Hubble constant with Type Ia supernovae as near-infrared standard candles
• Type Ia Supernovae are Good Standard Candles in the Near Infrared: Evidence from PAIRITEL
• The Type Ia supernova 2004S, a clone of SN 2001el, and the optimal photometric bands for extinction estimation
• Optical and IR observations of SN 2002dj: some possible common properties of fast expanding SNe Ia
• Investigating the Diversity of Type Ia Supernova Spectra with the Open-Source Relational Database Kaepora
• A Revised SALT2 Surface for Fitting Type Ia Supernova Light Curves
• Berkeley Supernova Ia Program: Data Release of 637 Spectra from 247 Type Ia Supernovae
• H-band light curves of Milky Way Cepheids via Difference Imaging

Cited by in corpus (1)

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