[Paper Review] Supernovae in 2023 (review): possible breakthroughs by late observations

Noam Soker|arXiv (Cornell University)|Nov 29, 2023

Gamma-ray bursts and supernovae106 references4 citations

TL;DR

This 2023 review proposes that late-stage observations of supernova remnants (SNRs) provide breakthrough evidence for the jittering jets explosion mechanism (JJEM) in core-collapse supernovae (CCSNe) and for a group of 'lonely white dwarf' (WD) scenarios in Type Ia SNe (SNe Ia). Point-symmetric morphologies in three CCSNRs and in SNR G1.9+0.3, along with the spherical Pa 30 remnant from SN 1181, strongly support jet-driven explosions and isolated WD progenitors, challenging the delayed neutrino mechanism and the dominance of standard double-degenerate or single-degenerate models.

ABSTRACT

I present a review of how late observations of supernovae, of the nebular phase, and much later of supernova remnants (SNRs), and their analysis in 2023 made progress towards possible breakthroughs in supporting the jittering jets explosion mechanism (JJEM) for core-collapse supernovae (CCSNe) and in introducing the group of lonely white dwarf (WD) scenarios for type Ia supernovae (SNe Ia). The new analyses of CCSN remnants (CCSNRs) reveal point-symmetric morphologies in a way unnoticed before in several CCSNRs. Qualitative comparison to multipolar planetary nebulae that are shaped by jets suggests that jets exploded these CCSNe, as predicted by the JJEM, but incompatible with the prediction of the delayed neutrino explosion mechanism. The spherical morphology of the ejecta Pa 30 of the historical type Iax supernova (SN Iax) of 1181 AD, which studies in 2023 revealed, is mostly compatible with the explosion of a lonely WD. Namely, at the explosion time, there is only a WD, without any close companion, although the WD was formed via a close binary interaction, i.e., binary merger. Identifying point-symmetry in SNR G1.9+0.3, a normal SN Ia and the youngest SN in the Galaxy, suggests an SN explosion of a lonely WD inside a planetary nebula (an SNIP). The group of lonely WD scenarios includes the core degenerate scenario and the double degenerate scenario with a merger to explosion delay (MED) time. SN Ia explosions of lonely WDs are common and might actually account for most (or even all) normal SNe Ia.

Motivation & Objective

• To evaluate late observations of supernovae and remnants to test explosion mechanisms for core-collapse and Type Ia SNe.
• To challenge the dominance of the delayed neutrino explosion mechanism by presenting morphological evidence favoring the jittering jets explosion mechanism (JJEM).
• To establish the group of 'lonely white dwarf' scenarios—including core-degenerate and double-degenerate with merger-to-explosion delay (MED)—as central to understanding normal and peculiar SNe Ia.
• To argue that observational data from 2023, particularly in the nebular and remnant phases, support a broader set of progenitor scenarios beyond the standard single-degenerate and double-degenerate models.

Proposed method

• Analysis of high-resolution imaging and spectral data from 2023 to identify point-symmetric morphologies in core-collapse supernova remnants (CCSNRs), defined by symmetric features such as lobes, clumps, and ears with respect to the remnant center.
• Comparison of observed SNR morphologies with theoretical predictions of the JJEM, which links jet activity during and after core-collapse to the formation of energetic magnetars and multipolar structures.
• Use of nebular-phase observations—especially of Pa 30 (SN 1181) and G1.9+0.3—to infer progenitor systems, focusing on spherical symmetry and point-symmetry as indicators of isolated white dwarfs.
• Application of morphological classification to identify previously unnoticed point-symmetry in three CCSNRs (noted in Figures 1–3) and a speculative detection in CTB 1.
• Integration of data from multiple 2023 studies on SNRs, including those from Chandra, Hubble, and ground-based telescopes, to assess consistency with the JJEM and lonely WD models.
• Rejection of models predicting 'failed supernovae' under the delayed neutrino mechanism, based on lack of observational support and inconsistency with observed jet-driven morphologies.

Figure 1: The CCSNR N63A has a point-symmetric morphology. A Chandra X-ray image of SNR N63A (logarithmic-scale $0.3-7.0{~{}\rm keV}$ ). The green lines and the small-yellow writings are from the original figure of Karagöz et al. ( 2023 ) . The red-solid lines, the dashed-blue lines, and the red and

Experimental results

Research questions

• RQ1 Do point-symmetric morphologies in core-collapse supernova remnants provide evidence for the jittering jets explosion mechanism (JJEM) over the delayed neutrino mechanism?
• RQ2 Can the spherical morphology of Pa 30, the remnant of SN 1181, be explained by an explosion of a lonely white dwarf without a close companion?
• RQ3 Does the point-symmetric structure in SNR G1.9+0.3 support the scenario of a Type Ia supernova occurring inside a planetary nebula (SNIP) and thus a lonely WD progenitor?
• RQ4 To what extent do nebular-phase observations of SNe Ia in 2023 constrain the validity of the standard single-degenerate and double-degenerate models versus the lonely WD scenarios?
• RQ5 How do late observations of supernovae and remnants challenge the long-standing assumption that only two progenitor scenarios (SD and DD) explain the diversity of SNe Ia?

Key findings

• Three core-collapse supernova remnants (CCSNRs) exhibit previously unnoticed point-symmetric morphologies, with symmetric features such as lobes and ears, strongly supporting the jittering jets explosion mechanism (JJEM).
• The nebular-phase remnant Pa 30 of the historical SN 1181 AD shows a large-scale spherical morphology, which is most compatible with the explosion of a lonely white dwarf, despite the WD's prior formation via binary merger.
• Point-symmetric morphology in SNR G1.9+0.3—the youngest Galactic SN Ia—provides the strongest evidence to date for a Type Ia supernova occurring inside a planetary nebula (SNIP), supporting the lonely WD scenario.
• The identification of point-symmetry in three CCSNRs and the spherical symmetry of Pa 30 collectively challenge the delayed neutrino explosion mechanism, which predicts failed supernovae and lacks such morphological features.
• The review argues that the group of 'lonely white dwarf' scenarios—including core-degenerate and double-degenerate with merger-to-explosion delay (MED)—may account for most or all normal SNe Ia, challenging the dominance of standard SD and DD models.
• Observational data from 2023 suggest that more than two progenitor scenarios (4–5) are required to explain the diversity of normal and peculiar SNe Ia, urging abandonment of the exclusive focus on SD and DD models.

Figure 2: The point-symmetric morphology of the Vela SNR, as identified by Soker ( 2023d ) . The ROSAT X-ray image is from Aschenbach et al. ( 1995 ) , and the figure is adapted from figure 1 of Sapienza et al. ( 2021 ) . Clumps A to F were identified by Aschenbach et al. 1995 . The white AG-line an