The Luminous and Carbon-Rich Supernova 2006gz: A Double Degenerate Merger?

TL;DR

SN 2006gz exhibits characteristics of a super-Chandrasekhar mass Type Ia supernova, with strong unburned carbon signatures, slow light curve decline, and high nickel production, supporting a double degenerate merger origin.

Contribution

This paper presents evidence that SN 2006gz is a super-Chandrasekhar mass supernova resulting from a double degenerate merger, based on spectral and light curve analysis.

Findings

Strong unburned carbon signature detected

Slowest fading light curve observed in Type Ia supernova

Estimated nickel mass of ~1.2 solar masses

Abstract

Spectra and light curves of SN 2006gz show the strongest signature of unburned carbon and one of the slowest fading light curves ever seen in a type Ia event (Delta m_15 = 0.69 +/- 0.04). The early-time Si II velocity is low, implying it was slowed by an envelope of unburned material. Our best estimate of the luminosity implies M_V = -19.74 and the production of ~ 1.2 M_sun of 56Ni. This suggests a super-Chandrasekhar mass progenitor. A double degenerate merger is consistent with these observations.