Violent mass ejection by the progenitors of the brightest planetary nebulae: supernova progenitors

TL;DR

The paper investigates why the brightest Galactic planetary nebulae (PNe) exhibit distinctive, jet-driven morphologies and whether these features reflect binary evolution pathways that could produce Type Ia supernovae. By analyzing the morphologies of the 13 brightest PNe, the author identifies prevalent multipolar, jet-activity signatures and small departures from pure point symmetry, arguing these arise from violent binary interactions rather than triple-star systems. The study further discusses the youngest Galactic SN Ia, SNR G1.9+0.3, as a potential SNIP—an SN Ia exploding inside a PN—consistent with a core-degenerate or near-close WD–core interaction scenario. The findings suggest that many bright PNe host merger remnants or massive WD systems and that binary evolution plays a crucial role in shaping the brightest PNe and in shaping SN Ia progenitor channels, with implications for the PNLF cutoff and PN–SN connections.

Abstract

I examine the morphologies of the brightest planetary nebulae (PNe) in the Milky Way Galaxy and conclude that violent binary interaction processes eject the main nebulae of the brightest PNe. The typical morphologies of the brightest PNe are multipolar, namely have been shaped by two or more major jet-launching episodes at varying directions, and possess small to medium departures from pure point symmetry. I discuss some scenarios, including a rapid onset of a common envelope interaction and the merger of the companion, mainly a white dwarf, with the asymptotic giant branch core at the termination of the common envelope. Some of these might be progenitors of type Ia supernovae (SNe Ia), as I suggest for SNR G1.9+0.3, the youngest SN Ia in the Galaxy.

Figures (5)

• Figure 1: Two panels from MoragaBaezetal2023 (their figure 10) of NGC 7027. On the left the red color depicts the Pa$\beta$/H$\beta$ line ratio, the green is extinction-corrected H$\alpha$ emission, and the blue is 1.3 mm radio continuum from Bublitzetal2023. On the right panel, MoragaBaezetal2023 schematically mark some structural components. They mark the three pairs of jets as Outflow 1, 2, and 3, where red/blue colors indicate the redshift/blueshift. Also marked are the nebula’s outer ring system, central elliptical shell, and equatorial belt. I added double-lined yellow arrows that point to morphological features that depart from pure point symmetry, as the insets indicate.
• Figure 2: Left: An HST image of NGC 6572 in H$\alpha$ (red), H$\beta$ (dark blue), oxygen (blue), and a yellow broadband filter (green) (credit: ESA/Hubble & NASA). I indicated departures from point symmetry. For more details on the multipolar structure see, e.g., Bandyopadhyayetal2023. The marks emphasize the three properties of (1) multipolar morphology, (2) departure from symmetry, and (3) non-messy morphology (only a small to moderate departure from pure point symmetry). Upper right: an HST image of IC 4670 (Hb 6; Chambersetal2016). Lower right: K3-17 (from Steffenetal2013).
• Figure 3: Six bright PNe, from upper left to lower right. An [O iii] image of M1-40 (Schwarzetal1992), an HST [N ii] image of NGC 6369 RamosLariosetal2012, an image of NGC 7354 from HST site (where more details can be found; credit ESA/Hubble & NASA), NGC 7662 (from the Chandra site based on Kastneretal2012), an HST [N ii] (log flux scale) image of NGC 6567 from Danehkar2022, and an HST image of NGC 7026 from the HST site (credit ESA/Hubble & NASA).
• Figure 4: Upper left: NGC 2440 (The HST site where more details can be found; credit: NASA, ESA, and K. Noll, STScI). Upper right: An [O iii] image in log scale of the PN NGC 6210 (Henneyetal2021). I added two S-shaped double-headed arrows to mark the S-shaped pairs of lobes. Bottom: an HST image of NGC 6537 (credit: SA & Garrelt Mellema). It has a large-scale bipolar morphology, but with clear departures from pure point symmetry and a multipolar morphology in the inner (white) region.
• Figure 5: An X-ray image image of SNR G1.9+0.3 with CO contours from Enokiyaetal2023. The ellipse and the coordinate lines are in the original image. Left panel: an image with annotations from Soker2023SNRG1903 to present the point symmetric morphology: a mark of the two ears and the double-headed arrows (DHA), including dashed line continuations. DHA-a to DHA-f point at twin clumps of a point symmetric structure, while DHA-$\tau$ is a tentative pair because the clumps are small and faint. The two white double-headed arrows point at pairs of clumps that require a different analysis as presented on the right panel (from Soker2023SNRG1903). The right panel includes the identification of the arc at the base of the upper (western) ear by a white dashed line, and its three peaks with dashed black lines. This is rotated around itself by $180^\circ$ and matched to the arc at the base of the bottom (eastern) ear, as the inset indicates. This procedure reveals a $9^\circ$ bend point symmetry of the two ears (DHA-0) and of the two base arcs (DHA-1 to DHA-3).