# Constraints on the physical properties of Type Ia supernovae from photometry

## TL;DR

This study analyzes 17 Type Ia supernovae using multi-color photometry to derive physical parameters like ejecta mass and Ni56 content, comparing observations with theoretical models to understand their properties.

## Contribution

It provides new constraints on supernova ejecta properties by combining light curve fitting with color evolution analysis and model comparisons.

## Key findings

- Consistent Ni56 mass estimates from color and bolometric data.
- Correlations between ejecta parameters and decline rate.
- Constraints on ejecta mass and opacity from Arnett-model fits.

## Abstract

We present a photometric study of 17 Type Ia supernovae (SNe) based on multi-color (Bessell BVRI) data taken at Piszkesteto mountain station of Konkoly Observatory, Hungary between 2016 and 2018. We analyze the light curves (LCs) using the publicly available LC-fitter SNooPy2 to derive distance and reddening information. The bolometric LCs are fit with a radiation-diffusion Arnett-model to get constraints on the physical parameters of the ejecta: the optical opacity, the ejected mass and the expansion velocity in particular. We also study the pre-maximum (B-V) color evolution by comparing our data with standard delayed detonation and pulsational delayed detonation models, and show that the Ni56 masses of the models that fit the (B-V) colors are consistent with those derived from the bolometric LC fitting. We find similar correlations between the ejecta parameters (e.g. ejecta mass, or Ni56 mass vs decline rate) as published recently by Scalzo et al. (2019).