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

Keiichi Maeda, Takaya Nozawa, Kentaro Motohara

Published 1970-01-01, updated 2014-11-14Version 1

Circumstellar (CS) environment is a key in understanding progenitors of type Ia supernovae (SNe Ia) as well as an origin of peculiar extinction property toward SNe Ia for cosmological application. It has been suggested that multiple em scatterings of SN photons on CS dust might explain a non-standard reddening law. In this paper, we investigate an effect of re-emissions of SN photons by CS dust in the Infrared (IR) wavelengths. We show that this effect allows observed IR light curves to be used to place a constraint on position/size and the amount of CSM dust. We apply the method to observed NIR SN Ia samples, showing that meaningful upper limits, even under conservative assumptions, on the CS dust mass can be derived. We thereby clarify a difficulty of the CS dust scattering model to be 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, environment at the interstellar scale should be responsible for the non-standard extinction law. Furthermore, deeper limits can be obtained by utilizing 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 10^{16} cm, Mdot <~ 10^{-5} - 10^{-6} Msun/yr up to 10^{17} cm. While not as strong as the radio/X-ray limit placed below a few x 10^{16} cm, our method provides a possibility to probe the CS property at the larger scale, corresponding to the mass loss rate further toward the past, highlighting the importance of the NIR information from early to late phases.