Article_Dobbie_2002_Alpha_Elem_Abund_PNG1359559.pdf (451.21 kB)
The alpha-element abundances in the most oxygen-poor planetary nebula PNG 135.9+55.9
journal contribution
posted on 2023-05-17, 14:41 authored by Richer, MG, Tovmassian, G, Stasinska, G, Jameson, RF, Dobbie, PD, Veillet, C, Gutierrez, C, Prada, FWe present extensive new spectroscopy and imaging of PNG 135.9+55.9. We use these data as constraints to photoionization models to derive limits on the oxygen abundance. We find that PNG 135.9+55.9 has an oxygen abundance less than 1/50 of the solar value. Our models favour a value of 12 + log O/H between 5.8 and 6.5 dex, confirming that PNG 135.9+55.9 is the most oxygen-poor planetary nebula known (Tovmassian et al. 2001). We also derive Ne/O = 0.5 ± 0.3, S/O < 0.094, and Ar/O < 0.23. Although the value of Ne/O is nominally high, it need not imply that the progenitor of PNG 135.9+55.9 converted any of its initial oxygen abundance to neon. The helium abundance appears to be very low, He/H ~ 0.08, but a precise determination will require a much more detailed study. We find that Hα/Hβ is lower than expected and perhaps variable, a finding for which we have no clear explanation.
History
Publication title
Astronomy and Astrophysics: A European JournalVolume
395Pagination
929 - 941ISSN
0004-6361Department/School
School of Natural SciencesPublisher
E D P SciencesPlace of publication
7, Ave Du Hoggar, Parc D Activites Courtaboeuf, Bp 112, Les Ulis Cedexa, France, F-91944Rights statement
Copyright 2002 ESORepository Status
- Open