The case of NGC 6302: the impact of shocks in the derivation of nitrogen abundances

Author(s)

Lago, P. J. A. ^{[1, 2]} ; Costa, R. D. D. ^[1] ; Faundez-Abans, M. ^[2] ; Maciel, W. J. ^[1]

Affiliation

^[1] Univ Sao Paulo, IAG, Dept Astron, Rua Matao, 1226 Cidade Univ, Sao Paulo, SP - Brazil

^[2] LNA, R Estados Unidos, 154 Nacoes, Itajuba, MG - Brazil

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 489, n. 2, p. 2923-2929, OCT 2019.
• Web of Science Citations: 0

Abstract

High nitrogen abundance is characteristic of Type I planetary nebulae, as well as their highly filamentary structure. In the present work, we test the hypothesis of shocks as a relevant excitation mechanism for a Type I nebula, NGC 6302, using recently released diagnostic diagrams to distinguish shocks from photoexcitation. The construction of the diagrams depends on emission-line ratios and kinematical information. NGC 6302 shows the relevance of shocks in peripheral regions and their importance to the whole nebula. Using shocks, we question the usual assumption of ionization correction factor calculation, justifying a warning regarding broadly used abundance derivation methods. From kinematical analysis, we derive a new distance for NGC 6302 of 805 +/- 143 pc. (AU)

• FAPESP's process: 10/18835-3 - Planetary nebulae, stars and chemical evolution of stellar systems
• Grantee: Roberto Dell'Aglio Dias da Costa
• Support Opportunities: Research Projects - Thematic Grants