Extended Optical/NIR Observations of Type Iax Supernova 2014dt: Possible Signatures of a Bound Remnant

TL;DR

This study presents extensive optical and near-infrared observations of SN 2014dt, revealing slow evolution and signatures consistent with a bound remnant, supporting the weak deflagration model for Type Iax supernovae.

Contribution

It provides detailed observational evidence for a bound white dwarf remnant in SN 2014dt, supporting the weak deflagration explosion model for Type Iax supernovae.

Findings

Slower expansion velocities compared to other Type Iax SNe.

Light curve and spectral evolution are significantly slower in late phases.

Evidence of an optically thick component trapping gamma-ray energy.

Abstract

We present optical and near-infrared observations of the nearby Type Iax supernova (SN) 2014dt from 14 to 410 days after the maximum light. The velocities of the iron absorption lines in the early phase indicated that SN 2014dt showed slower expansion than the well-observed Type Iax SNe 2002cx, 2005hk and 2012Z. In the late phase, the evolution of the light curve and that of the spectra were considerably slower. The spectral energy distribution kept roughly the same shape after ~100 days, and the bolometric light curve flattened during the same period. These observations suggest the existence of an optically thick component that almost fully trapped the {\gamma}-ray energy from 56 Co decay. These findings are consistent with the predictions of the weak deflagration model, leaving a bound white dwarf remnant after the explosion.