Alpha-element abundance patterns in star-forming regions of the local Universe

Fuente: arXiv
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Main Authors: Esteban, C., Méndez-Delgado, J. E., García-Rojas, J., Arellano-Córdova, K. Z., Rosales-Ortega, F. F., Orte-García, M., Reyes-Rodríguez, E., Carigi, L., Amayo, A.
Format: Preprint
Published: 2025
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author Esteban, C.
Méndez-Delgado, J. E.
García-Rojas, J.
Arellano-Córdova, K. Z.
Rosales-Ortega, F. F.
Orte-García, M.
Reyes-Rodríguez, E.
Carigi, L.
Amayo, A.
author_facet Esteban, C.
Méndez-Delgado, J. E.
García-Rojas, J.
Arellano-Córdova, K. Z.
Rosales-Ortega, F. F.
Orte-García, M.
Reyes-Rodríguez, E.
Carigi, L.
Amayo, A.
contents (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 galaxies (SFGs) of the local Universe. Using the DEep Spectra of Ionised REgions Database (DESIRED) Extended project (DESIRED-E), which includes spectra with direct electron temperature determinations, we homogeneously derive physical conditions and chemical abundances for all objects. Various ionisation correction factor (ICF) schemes are analyzed for Ne, S, and Ar to identify the most reliable abundance estimates. Our findings indicate that one of the tested ICF schemes better reproduces the Ne/O, S/O, and Ar/O trends. Ne/O ratios in HII regions display large dispersion and no clear dependence on O/H, suggesting that current ICF(Ne) schemes fail for these objects. However, SFGs show consistent linear relations with slightly positive slopes for log(Ne/O) vs. 12+log(O/H) or 12+log(Ne/H), likely influenced by metallicity-dependent O dust depletion and ICF effects. The log(S/O) vs. 12+log(O/H) distribution is largely constant, especially for HII regions or combined samples (SFGs + HII regions). Conversely, log(S/O) vs. 12+log(S/H) shows a tight linear fit with a positive slope, flattening at 12+log(S/H) < 6.0, suggesting S contributions from SNe Ia. For log(Ar/O) vs. 12+log(O/H), similar trends emerge for HII regions and SFGs, independent of ionisation degree or ICF(Ar). A slight log(Ar/O) decrease with increasing 12+log(O/H) contrasts with log(Ar/O) vs. 12+log(Ar/H), which shows a small positive slope, indicating a possible minor Ar contribution from SNe Ia.
format Preprint
id arxiv_https___arxiv_org_abs_2501_13586
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Alpha-element abundance patterns in star-forming regions of the local Universe
Esteban, C.
Méndez-Delgado, J. E.
García-Rojas, J.
Arellano-Córdova, K. Z.
Rosales-Ortega, F. F.
Orte-García, M.
Reyes-Rodríguez, E.
Carigi, L.
Amayo, A.
Astrophysics of Galaxies
(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 galaxies (SFGs) of the local Universe. Using the DEep Spectra of Ionised REgions Database (DESIRED) Extended project (DESIRED-E), which includes spectra with direct electron temperature determinations, we homogeneously derive physical conditions and chemical abundances for all objects. Various ionisation correction factor (ICF) schemes are analyzed for Ne, S, and Ar to identify the most reliable abundance estimates. Our findings indicate that one of the tested ICF schemes better reproduces the Ne/O, S/O, and Ar/O trends. Ne/O ratios in HII regions display large dispersion and no clear dependence on O/H, suggesting that current ICF(Ne) schemes fail for these objects. However, SFGs show consistent linear relations with slightly positive slopes for log(Ne/O) vs. 12+log(O/H) or 12+log(Ne/H), likely influenced by metallicity-dependent O dust depletion and ICF effects. The log(S/O) vs. 12+log(O/H) distribution is largely constant, especially for HII regions or combined samples (SFGs + HII regions). Conversely, log(S/O) vs. 12+log(S/H) shows a tight linear fit with a positive slope, flattening at 12+log(S/H) < 6.0, suggesting S contributions from SNe Ia. For log(Ar/O) vs. 12+log(O/H), similar trends emerge for HII regions and SFGs, independent of ionisation degree or ICF(Ar). A slight log(Ar/O) decrease with increasing 12+log(O/H) contrasts with log(Ar/O) vs. 12+log(Ar/H), which shows a small positive slope, indicating a possible minor Ar contribution from SNe Ia.
title Alpha-element abundance patterns in star-forming regions of the local Universe
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2501.13586