Planetary nebulae in the Small Magellanic Cloud. Issue 4 (26th May 2016)

• Record Type: Journal Article
• Authors: Ventura, P.; Stanghellini, L.; Di Criscienzo, M.; García-Hernández, D. A.; Dell'Agli, F.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 460:Issue 4(2016)
• Page Start: 3940
• Page End: 3949
• Publication Date: 2016-05-26
• Subjects: Stars: abundances -- Stars: AGB and post-AGB -- Stars: carbon; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw1254
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract : We analyse the planetary nebulae (PNe) population of the Small Magellanic Cloud (SMC), based on evolutionary models of stars with metallicities in the range 10 −3 ≤ Z ≤ 4 × 10 −3 and mass 0.9 M⊙ < M < 8 M⊙, evolved through the asymptotic giant branch (AGB) phase. The models used account for dust formation in the circumstellar envelope. To characterize the PNe sample of the SMC, we compare the observed abundances of the various species with the final chemical composition of the AGB models: this study allows us to identify the progenitors of the PNe observed, in terms of mass and chemical composition. According to our interpretation, most of the PNe descend from low-mass ( M < 2 M⊙ ) stars, which become carbon rich, after experiencing repeated third dredge-up episodes, during the AGB phase. A fraction of the PNe showing the signature of advanced CNO processing are interpreted as the progeny of massive AGB stars, with mass above ∼6 M⊙, undergoing strong hot bottom burning. The differences with the chemical composition of the PNe population of the Large Magellanic Cloud is explained on the basis of the diverse star formation history and age–metallicity relation of the two galaxies. The implications of this study for some still highly debated points regarding the AGB evolution are also commented.