7 papers
Investigating the electron temperature of [Ar IV] in planetary nebulae using the DESIRED database
J. GarcÃa-Rojas, E. Reyes-RodrÃguez, J. E. Méndez-Delgado +9
(Abridged) We investigate the behaviour of the electron temperature derived from [Ar IV] lines, Te([Ar IV]), in a sample of PNe to characterize the thermal structure of high-excita…
The DESIRED electron temperature relations in star-forming regions of the local Universe
M. Orte-GarcÃa, C. Esteban, J. GarcÃa-Rojas +7
(Abridged) Aims. We present a homogeneous observational study of electron temperature () relations between ionic species: ([N II]), ([O II]), $T_{\…
The DESIRED strong-line calibrations: I. New empirical metallicity relations for the local and high-redshift universe
F. F. Rosales-Ortega, J. E. Méndez-Delgado, J. U. Guerrero-González +16
We present the most comprehensive set of empirical optical strong-line metallicity calibrations to date, based on the DEep Spectra of Ionised REgions Database (DESIRED), the larges…
Alpha-element abundance patterns in star-forming regions of the local Universe
C. Esteban, J. E. Méndez-Delgado, J. GarcÃa-Rojas +6
(Abridged) We reassess the alpha-element abundance ratios (Ne/O, S/O, Ar/O) with respect to metallicity in ~1000 spectra of Galactic and extragalactic HII regions and star-forming…
Generalized ([OIII])-(HeI) Discrepancies in Ionized Nebulae: Possible Evidence of Case B Deviations and Temperature Inhomogeneities
J. E. Méndez-Delgado, E. D. Skillman, E. Aver +11
The physics of recombination lines (RLs) in the HeI singlet system is expected to be relatively simple, supported by accurate atomic models. We examine the intensities of HeI singl…
Chlorine abundances in star-forming regions of the local Universe
M. Orte-GarcÃa, C. Esteban, J. E. Méndez-Delgado +4
Aims. We study the behaviour of Cl abundance and its ratios with respect to O, S and Ar abundances in a sample of more than 200 spectra of Galactic and extragalactic H ii regions a…