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arXiv · 1701.04411

Using photo-ionisation models to derive carbon and oxygen gas-phase abundances in the rest UV

Enrique Pérez-Montero·Ricardo Amorín
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Abstract

We present a new method to derive oxygen and carbon abundances using the ultraviolet (UV) lines emitted by the gas-phase ionised by massive stars. The method is based on the comparison of the nebular emission-line ratios with those predicted by a large grid of photo-ionisation models. Given the large dispersion in the O/H - C/O plane, our method firstly fixes C/O using ratios of appropriate emission lines and, in a second step, calculates O/H and the ionisation parameter from carbon lines in the UV. We find abundances totally consistent with those provided by the direct method when we apply this method to a sample of objects with an empirical determination of the electron temperature using optical emission lines. The proposed methodology appears as a powerful tool for systematic studies of nebular abundances in star-forming galaxies at high redshift.

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Enrique Pérez-Montero, Ricardo Amorín. 2017-01-16. Using photo-ionisation models to derive carbon and oxygen gas-phase abundances in the rest UV. https://doi.org/10.1093/mnras/stx186

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