Study on the Abundance Discrepancy Problem in the Magellanic Clouds

Toribio San Cipriano, L.; Esteban, C.; Domínguez-Guzmán, G.; García-Rojas, J.
Bibliographical reference

Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society held on July 18-22, 2016, in Bilbao, Spain, ISBN 978-84-606-8760-3. S. Arribas, A. Alonso-Herrero, F. Figueras, C. Hernández-Monteagudo, A. Sánchez-Lavega, S. Pérez-Hoyos (eds.), 2017, p. 263-268

Advertised on:
3
2017
Number of authors
4
IAC number of authors
3
Citations
0
Refereed citations
0
Description
We present chemical abundances of carbon (C) and oxygen (O) in the Large and Small Magellanic Clouds from deep and high-quality optical spectra of H II regions. The data have been taken using the Ultraviolet-Visual Echelle Spectrograph at the 8.2-m Very Large Telescope with the goal of detecting the faint C II and O II recombination lines. For all the objects of the sample, we determine C^{2+}abundances from recombination lines and O^{2+} abundances from recombination lines and collisionally excited lines. In addition, we calculate the abundance discrepancy factors (ADFs) for O^{2+} and C^{2+}, as well as the O/H, C/H and C/O ratios. We study the behaviour of the ADF comparing the values obtained in the Magellanic Clouds with those obtained for other H_{II} regions in different galaxies. We also compare the nebular and stellar abundances in two regions of the sample. Finally, we discuss the chemical evolution of the MCs through the O/H, C/H and C/O radial gradients and the changes of the C/O ratio as a function of O/H.