Delayed Wind Onset in Pa 30, the Remnant of Type Iax SN 1181

TL;DR

This paper investigates the delayed wind onset in the supernova remnant Pa 30, associated with SN 1181, proposing that delayed ignition of fallback material explains the observed shock and supports a pure-deflagration progenitor scenario.

Contribution

It introduces a model for delayed wind ignition in Pa 30, linking it to a hot post-explosion white dwarf core and supporting the Type Iax supernova progenitor scenario.

Findings

Delayed wind onset occurs centuries after explosion.

A hot WD core ($T_c \,\simeq\ 6\times10^8$ K) is necessary for delay.

Supports the pure-deflagration progenitor scenario.

Abstract

Pa 30 is the recently identified remnant of the historical supernova SN 1181, likely a Type Iax event, and a nebula surrounding the central white dwarf launching a fast wind ($\sim10^9~\cm~\s^{-1}$) is observed in optical and infrared bands. X-ray observations show that this wind collides with the surrounding material and produces a termination shock, and the observed extent of the shock indicates that the wind started blowing centuries after 1181 A.D. rather than immediately after the SN explosion. We propose that the wind is triggered by delayed ignition of fallback carbon-rich material on the WD surface and investigate the conditions that reproduce such delayed ignition. We show that producing delays of several centuries requires a relatively hot post-explosion WD core with a temperature $T_c \simeq 6\times10^8~\mathrm{K}$. This supports the pure-deflagration progenitor scenario for Type Iax SN 1181, which implies the presence of a He star companion inside Pa~30; we also discuss why such a potential He star has not been detected and its prospects for discovery by future observations.