Circumstellar interaction in type Ibn supernovae and SN 2006jc

TL;DR

This paper investigates the peculiar light curves and spectra of Type Ibn supernovae, especially SN 2006jc, highlighting the role of early circumstellar interaction and dust formation in shaping their observed properties.

Contribution

It provides a detailed analysis of circumstellar interaction effects and dust condensation in Type Ibn supernovae, supported by Monte Carlo modeling of spectral lines.

Findings

Circumstellar interaction explains high luminosity and rapid flux rise.

Dust condenses in the cool dense shell around day 50.

He I line profiles are affected by dust occultation, indicating dust in the shell.

Abstract

I analyse peculiar properties of light curve and continua of enigmatic Ibn supernovae, including SN 2006jc, and argue in favour of the early strong circumstellar interaction. This interaction explains the high luminosity and fast flux rise of SN 1999cq, while the cool dense shell formed in shocked ejecta can explain the smooth early continuum of SN 2000er and unusual blue continuum of SN 2006jc. The dust is shown to condense in the cool dense shell at about day 50. Monte Carlo modelling of the He I 7065 \AA line profile affected by the dust occultation supports a picture, in which the dust resides in the fragmented cool dense shell, whereas He I lines originate from circumstellar clouds shocked and fragmented in the forward shock wave.