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IC10: the history of the nearest starburst galaxy through its Planetary Nebula and H ii region populations†
Article first published online: 20 JUL 2009
DOI: 10.1111/j.1365-2966.2009.15124.x
© 2009 The Authors. Journal compilation © 2009 RAS
Issue
Monthly Notices of the Royal Astronomical Society
Volume 398, Issue 1, pages 280–292, September 2009
Additional Information
How to Cite
Magrini, L. and Gonçalves, D. R. (2009), IC10: the history of the nearest starburst galaxy through its Planetary Nebula and H ii region populations. Monthly Notices of the Royal Astronomical Society, 398: 280–292. doi: 10.1111/j.1365-2966.2009.15124.x
Publication History
- Issue published online: 19 AUG 2009
- Article first published online: 20 JUL 2009
- Accepted 2009 May 22. Received 2009 May 22; in original form 2009 March 19
- Abstract
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- References
- Cited By
Keywords:
- galaxies: abundances;
- galaxies: evolution;
- Local Group;
- H ii regions
ABSTRACT
We report the results of spectroscopic observations, obtained with the Gemini North Multi-Object Spectrograph, of nine planetary nebulae (PNe) and 15 H ii regions located in the 5.5 × 5.5 arcmin2 inner region of the nearby starburst galaxy IC10. Twelve new candidates PNe have been discovered during our pre-imaging phase. Nine of them have been spectroscopically confirmed. The direct availability of the electron temperature diagnostics in several nebulae allowed an accurate determination of the metallicity map of IC10 at two epochs: the present-time from H ii regions and the old/intermediate-age from PNe. We found a non-homogeneous distribution of metals at both epochs, but similar average abundances were found for the two populations. The derived age–metallicity relation shows a little global enrichment interpreted as the loss of metals by supernova winds and to differential gas outflows. Finally, we analysed the production of oxygen – through the third dredge-up – in the chemical abundance patterns of the PN populations belonging to several dwarf irregular galaxies. We found that the third dredge-up of oxygen is a metallicity dependent phenomenon occurring mainly for 12 + log(O/H) ≤ 7.7 and substantially absent in IC10 PNe.