Addressing type Ia supernova color variability with a linear spectral template
arXiv:2310.02329 · doi:10.1016/j.ascom.2024.100866
Abstract
Type Ia Supernovae (SNeIa) provided the first evidence of an accelerated expansion of the universe and remain a valuable probe to cosmology. They are deemed standardizable candles due to the observed correlations between its luminosity and photometric quantities. This characteristic can be exploited to estimate cosmological distances after accounting for the observed variations. There is however a remaining dispersion unaccounted for in the current state-of-the-art standardization methods. In an attempt to explore this issue, we propose a simple linear 3-component rest-frame flux description for a light-curve fitter. Since SNIa intrinsic color index variations are expected to be time-dependent, our description builds-up upon the mathematical expression of the well known SALT2 for rest-frame flux, whilst we drop the exponential factor and add an extra model component with time and wavelength dependencies. The model components are obtained by performing either Principal Component Analysis (PCA) or Factor Analysis (FA) onto a representative training set. The constraining power of the Pure Expansion Template for Supernovae (PETS), is evaluated and we found compatible results with SALT2 for and within 68% uncertainty between the two models, with PETS' fit parameters exhibiting non negligible linear correlations with SALT2' parameters. For both model versions we verified that the first component describes mainly color index variations, as a dominant effect on SNIa spectra. The model nuisance parameter which multiplies the color index variation-like fit parameter shows evolution with redshift in an initial binned cosmology analysis. This behavior can be due to selection effects. Overall, our model shows promise, as there are still a few aspects to be refined; however, it still falls short in reducing the unaccounted dispersion.
References in corpus (14)
- New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
- Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report
- 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
- An Analysis of the Shapes of Interstellar Extinction Curves. V. The IR-Through-UV Curve Morphology
- CfA3: 185 Type Ia Supernova Light Curves from the CfA
- The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary
- SNLS3: Constraints on Dark Energy Combining the Supernova Legacy Survey Three Year Data with Other Probes
- The Carnegie Supernova Project I: Third Photometry Data Release of Low-Redshift Type Ia Supernovae and Other White Dwarf Explosions
- SALT3: An Improved Type Ia Supernova Model for Measuring Cosmic Distances
- Union Through UNITY: Cosmology with 2,000 SNe Using a Unified Bayesian Framework
- A metric space for type Ia supernova spectra
- Synergies between Vera C. Rubin Observatory, Nancy Grace Roman Space Telescope, and Euclid Mission: Constraining Dark Energy with Type Ia Supernovae