Detailed Spectral Modeling of a 3-D Pulsating Reverse Detonation Model: Too Much Nickel

TL;DR

This study presents detailed spectral modeling of a 3-D pulsating reverse detonation supernova model, revealing discrepancies such as excessive red flux and unusual features not typically observed in Type Ia supernovae.

Contribution

It introduces a novel 3-D explosion model for Type Ia supernovae and provides detailed NLTE synthetic spectra at multiple epochs, highlighting key spectral features and model limitations.

Findings

Prominent Si II feature at maximum light

Presence of C II feature not typical in normal SNe Ia

Model spectra are intrinsically redder than observed supernovae

Abstract

We calculate detailed NLTE synthetic spectra of a Pulsating Reverse Detonation (PRD) model, a novel explosion mechanism for Type Ia supernovae. While the hydro models are calculated in 3-D, the spectra use an angle averaged hydro model and thus some of the 3-D details are lost, but the overall average should be a good representation of the average observed spectra. We study the model at 3 epochs: maximum light, seven days prior to maximum light, and 5 days after maximum light. At maximum the defining Si II feature is prominent, but there is also a prominent C II feature, not usually observed in normal SNe Ia near maximum. We compare to the early spectrum of SN 2006D which did show a prominent C II feature, but the fit to the observations is not compelling. Finally we compare to the post-maximum UV+optical spectrum of SN 1992A. With the broad spectral coverage it is clear that the iron-peak elements on the outside of the model push too much flux to the red and thus the particular PRD realizations studied would be intrinsically far redder than observed SNe Ia. We briefly discuss variations that could improve future PRD models.