Constraining the Amount of Circumstellar Matter and Dust around Type Ia Supernovae through Near-Infrared Echoes

TL;DR

This study uses near-infrared echoes from supernovae to constrain the amount and distribution of circumstellar dust, challenging previous scattering models and highlighting the interstellar environment's role in extinction properties.

Contribution

It introduces a method to constrain circumstellar dust around Type Ia supernovae using IR light curves, providing upper limits on dust mass and addressing scattering model limitations.

Findings

Upper limits on CS dust mass were derived from NIR observations.

The scattering model may only apply to a subset of highly reddened SNe Ia.

Interstellar environment likely influences the non-standard extinction law.

Abstract

The circumstellar (CS) environment is key to understanding progenitors of type Ia supernovae (SNe Ia), as well as the origin of a peculiar extinction property toward SNe Ia for cosmological application. It has been suggested that multiple scatterings of SN photons by CS dust may explain the non-standard reddening law. In this paper, we examine the effect of re-emission of SN photons by CS dust in the infrared (IR) wavelength regime. This effect allows the observed IR light curves to be used as a constraint on the position/size and the amount of CS dust. The method was applied to observed near-infrared (NIR) SN Ia samples; meaningful upper limits on the CS dust mass were derived even under conservative assumptions. We thereby clarify a difficulty associated with the CS dust scattering model as a general explanation for the peculiar reddening law, while it may still apply to a sub-sample of highly reddened SNe Ia. For SNe Ia in general, the environment at the interstellar scale appears to be responsible for the non-standard extinction law. Furthermore, deeper limits can be obtained using the standard nature of SN Ia NIR light curves. In this application, an upper limit of Mdot ~10^{-8}-10^{-7} Msun/yr (for the wind velocity of ~10 km/s) is obtained for a mass loss rate from a progenitor up to ~0.01 pc, and Mdot ~10^{-7}-10^{-6} Msun/yr up to ~0.1 pc.