The Peculiar Type Ib Supernova 2006jc: A WCO Wolf-Rayet Star Explosion

TL;DR

This paper models the evolution and explosion of a massive Wolf-Rayet star as the progenitor of supernova 2006jc, explaining its light curve, dust formation, and circumstellar interaction with detailed simulations.

Contribution

It provides a comprehensive theoretical model linking the progenitor's evolution, explosion dynamics, and observed features of SN 2006jc, highlighting the role of a WCO Wolf-Rayet star.

Findings

Progenitor was a massive WCO Wolf-Rayet star with extensive mass loss.

Explosion parameters include 4.9 solar masses ejecta and 10^52 ergs energy.

Circumstellar medium with flat density explains X-ray observations.

Abstract

We present a theoretical model for Type Ib supernova (SN) 2006jc. We calculate the evolution of the progenitor star, hydrodynamics and nucleosynthesis of the SN explosion, and the SN bolometric light curve (LC). The synthetic bolometric LC is compared with the observed bolometric LC constructed by integrating the UV, optical, near-infrared (NIR), and mid-infrared (MIR) fluxes. The progenitor is assumed to be as massive as $40M_\odot$ on the zero-age main-sequence. The star undergoes extensive mass loss to reduce its mass down to as small as $6.9M_\odot$, thus becoming a WCO Wolf-Rayet star. The WCO star model has a thick carbon-rich layer, in which amorphous carbon grains can be formed. This could explain the NIR brightening and the dust feature seen in the MIR spectrum. We suggest that the progenitor of SN 2006jc is a WCO Wolf-Rayet star having undergone strong mass loss and such massive stars are the important sites of dust formation. We derive the parameters of the explosion model in order to reproduce the bolometric LC of SN 2006jc by the radioactive decays: the ejecta mass $4.9M_\odot$, hypernova-like explosion energy $10^{52}$ ergs, and ejected $^{56}$Ni mass $0.22M_\odot$. We also calculate the circumstellar interaction and find that a CSM with a flat density structure is required to reproduce the X-ray LC of SN 2006jc. This suggests a drastic change of the mass-loss rate and/or the wind velocity that is consistent with the past luminous blue variable (LBV)-like event.