We present a possible evolutionary pathway to form planetary nebulae (PNe) with close neutron star (NS)–white dwarf (WD) binary central stars. By employing the binary population synthesis technique, we find that the evolution involves two common envelope evolution (CEE) phases and a core collapse supernova explosion between them that forms the NS. Later the lower mass star engulfs the NS as it becomes a red giant, a process that leads to the second CEE phase and to the ejection of the envelope. This leaves a hot horizontal branch star that evolves to become a helium WD and an expanding nebula. Both the WD and the NS power the nebula. The NS in addition might power a pulsar wind nebula inside the expanding PN. From our simulations we find that the Galactic formation rate of NS–WD PNe is $1.8 \times 10^{-5}\, {\rm yr}^{-1}$ while the Galactic formation rate of all PNe is $0.42 \, {\rm yr}^{-1}$. There is a possibility that one of the observed Galactic PNe might be a NS–WD PN, and a few NS–WD PNe might exist in the Galaxy. The central binary systems might be sources for future gravitational wave detectors like LISA, and possibly of electromagnetic telescopes.
Binary interactions dominate the evolution of massive stars, but their role is less clear for low- and intermediate-mass stars. The evolution of a spherical wind from an asymptotic giant branch (AGB) star into a nonspherical planetary nebula (PN) could be due to binary interactions. We observed a sample of AGB stars with the Atacama Large Millimeter/submillimeter Array (ALMA) and found that their winds exhibit distinct nonspherical geometries with morphological similarities to planetary nebulae (PNe). We infer that the same physics shapes both AGB winds and PNe; additionally, the morphology and AGB mass-loss rate are correlated. These characteristics can be explained by binary interaction. We propose an evolutionary scenario for AGB morphologies that is consistent with observed phenomena in AGB stars and PNe.
more » « less- NSF-PAR ID:
- 10192925
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- American Association for the Advancement of Science (AAAS)
- Date Published:
- Journal Name:
- Science
- Volume:
- 369
- Issue:
- 6510
- ISSN:
- 0036-8075
- Page Range / eLocation ID:
- p. 1497-1500
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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