The infrared echo of SN2010jl and its implications for shock breakout characteristics

TL;DR

This paper investigates the infrared echo observed in SN 2010jl, analyzing dust properties and shock breakout characteristics to understand the supernova's interaction with its circumstellar medium.

Contribution

It provides the first detailed modeling of the IR echo in SN 2010jl, constraining dust mass, location, and the shock breakout radiation properties.

Findings

The IR echo is caused by about 1.6e-4 solar masses of amorphous carbon dust at 2.2e16 cm.

The shock breakout produced a burst of radiation that influenced dust survival.

Dust survival constraints inform the properties of the initial shock breakout radiation.

Abstract

SN 2010jl is a Type IIn core collapse supernova whose radiative output is powered by the interaction of the SN shock wave with its surrounding dense circumstellar medium (CSM). After day ~60, its light curve developed a NIR excess emission from dust. This excess could be a thermal IR echo from pre-existing CSM dust, or emission from newly-formed dust either in the cooling postshock region of the CSM, or in the cooling SN ejecta. Recent analysis has shown that dust formation in the CSM can commence only after day ~380, and has also ruled out newly-formed ejecta dust as the source of the NIR emission. The early (< 380 d) NIR emission can therefore only be attributed to an IR echo. The H-K color temperature of the echo is about 1250 K. The best fitting model requires the presence of about 1.6e-4 Msun of amorphous carbon dust at a distance of 2.2e16 cm from the explosion. The CSM-powered luminosity is preceded by an intense burst of hard radiation generated by the breakout of the SN shock through the stellar surface. The peak burst luminosity seen by the CSM dust is significantly reduced by Thomson scattering in the CSM, but still has the potential of evaporating the dust needed to produce the echo. We show that the survival of the echo-producing dust provides important constraints on the intensity, effective temperature, and duration of the burst.