Reduce, reuse, recycle: Planetary nebulae as green galactic citizens

Abstract

Abstract. We review gas-phase abundances in PNe and describe their dual utility as archives of original progenitor metallicity via the α elements, as well as sources of processed material from nucleosynthesis during the star's evolution, i.e., C, N, and s-process elements. We describe the analysis of PN spectra to derive abundances and discuss the discrepancies that arise from different choices at each step. Abundance results for the Milky Way and Magellanic Clouds from various groups of investigators are presented; the observational results are compared with theoretical predictions of AGB stellar yields. Finally, we suggest areas where more work is needed to improve our abilities to determine abundances in PNe.

Planetary Nebulae: Sources of Enlightenment

“…Several good review papers have been published recently addressing the subjects of nebular physics and abundance determinations from recombination and collisionally excited lines. 6 Readers who are unfamiliar with these topics or who desire a refresher course are referred to articles by Kwitter & Henry (2011), Pérez-Montero (2017), Peimbert et al (2017), Peimbert (2019), andGarcía-Rojas (2020).…”

Nebular Spectroscopy: A Guide on H ii Regions and Planetary Nebulae

“…Long-slit optical spectra have been widely used in the literature to derive the physical conditions and ionic abundances of ionized nebulae. There are spectra of several hundreds of Galactic and extragalactic PNe and H II regions with resolutions better than ∼5 Å (see, for example, the compilations by Kwitter & Henry 2012;Maciel et al 2017). These spectra allow the detection of nebular lines such as [O III] λ4959, λ5007, [N II] λ6548, λ6583, [S II] λ6717, λ6731, as well as RLs from hydrogen, helium, and carbon (C II λ4267).…”

“…Some interesting recent reviews on chemical abundances of PNe were made by Kwitter & Henry (2012); Magrini et al (2012); Delgado-Inglada (2016); García-Rojas (2016).…”