New calibrations for estimating the N/O ratio in H II regions
Metadatos
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Oxford University Press
Materia
ISM: abundances (ISM:) H II regions Galaxies: abundances Galaxies: ISM Galaxies: spiral
Fecha
2022-04-07Referencia bibliográfica
Estrella Florido, Almudena Zurita, Enrique Pérez-Montero, New calibrations for estimating the N/O ratio in H II regions, Monthly Notices of the Royal Astronomical Society, Volume 513, Issue 2, June 2022, Pages 2006–2018, [https://doi.org/10.1093/mnras/stac919]
Patrocinador
Instituto de Salud Carlos III Spanish Government European Commission PID2020114414GB-I00 PID2020-113689GB-I00; 'Junta de Andalucia' (Spain) local government FQM108 AFQM-510-UGR20; State Agency for Research of the Spanish 'Ministerio de Ciencia, Innovacon y Universidades' through the 'Center of Excellence Severo Ochoa' SEV-2017-0709 PID2019107408GB-C44; Junta de Andalucia EXC/2011 FQM7058Resumen
We use a sample of 536 H II regions located in nearby spirals, with a homogeneous determination of their T e -based abundances, to obtain new empirical calibrations of the N2O2, N2S2, O3N2, and N2 strong-line indices to estimate the nitrogen-to-oxygen abundance ratio when auroral lines are not detected. All indices are strongly correlated with the T e -based log (N/O) for our H II re gion sample, ev en more strongly than with 12 + log (O/H). N2O2 is the most strongly correlated index, and the best fit to the log (N/O)–N2O2 relation is obtained with a second-order polynomial. The derived relation has a low dispersion (rms < 0.09 dex), being valid in the range −1.74 < N2O2 < 0.62 (or −1.81 < log (N/O) < −0.13). We have compared our calibration with previous ones and have discussed the differences between them in terms of the nature of the objects used as calibrators.