Empirical calibration for helium abundance determinations in Active Galactic Nuclei
Fuente:
arXiv
Salvato in:
| Autori principali: | , , , , , , , , , , , , |
|---|---|
| Natura: | Preprint |
| Pubblicazione: |
2024
|
| Soggetti: | |
| Accesso online: | |
| Tags: |
Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
|
| _version_ | 1866913378739421184 |
|---|---|
| author | Dors, O. L. Almeida, G. C. Oliveira, C. B. Flury, S. R. Riffel, R. Riffel, R. A. Cardaci, M. V. Hägele, G. F. Ilha, G. S. Krabbe, A. C. Arellano-Córdova, K. Z. Santos, P. C. Morais, I. N. |
| author_facet | Dors, O. L. Almeida, G. C. Oliveira, C. B. Flury, S. R. Riffel, R. Riffel, R. A. Cardaci, M. V. Hägele, G. F. Ilha, G. S. Krabbe, A. C. Arellano-Córdova, K. Z. Santos, P. C. Morais, I. N. |
| contents | For the first time, a calibration between the HeI $\lambda5876$/H$β$ emission line ratio and the helium abundance $y$=12+log(He/H) for Narrow line regions (NLRs) of Seyfert~2 Active Galactic Nuclei (AGN) is proposed. In this context, observational data (taken from the SDSS-DR15 and from the literature) and direct abundance estimates (via the $T_{\rm e}$-method) for a sample of 65 local ($z \: < \: 0.2$) Seyfert~2 nuclei are considered. The resulting calibration estimates the $y$ abundance with an average uncertainty of 0.02 dex. Applying our calibration to spectroscopic data containing only strong emission lines, it yields a helium abundance distribution similar to that obtained via the $T_{\rm e}$-method. Some cautions must be considered to apply our calibration for Seyfert~2 nuclei with high values of electron temperature ($\gtrsim\: 20\,000$ K) or ionization parameter ($\log U > -2.0$). |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2406_03259 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Empirical calibration for helium abundance determinations in Active Galactic Nuclei Dors, O. L. Almeida, G. C. Oliveira, C. B. Flury, S. R. Riffel, R. Riffel, R. A. Cardaci, M. V. Hägele, G. F. Ilha, G. S. Krabbe, A. C. Arellano-Córdova, K. Z. Santos, P. C. Morais, I. N. Astrophysics of Galaxies For the first time, a calibration between the HeI $\lambda5876$/H$β$ emission line ratio and the helium abundance $y$=12+log(He/H) for Narrow line regions (NLRs) of Seyfert~2 Active Galactic Nuclei (AGN) is proposed. In this context, observational data (taken from the SDSS-DR15 and from the literature) and direct abundance estimates (via the $T_{\rm e}$-method) for a sample of 65 local ($z \: < \: 0.2$) Seyfert~2 nuclei are considered. The resulting calibration estimates the $y$ abundance with an average uncertainty of 0.02 dex. Applying our calibration to spectroscopic data containing only strong emission lines, it yields a helium abundance distribution similar to that obtained via the $T_{\rm e}$-method. Some cautions must be considered to apply our calibration for Seyfert~2 nuclei with high values of electron temperature ($\gtrsim\: 20\,000$ K) or ionization parameter ($\log U > -2.0$). |
| title | Empirical calibration for helium abundance determinations in Active Galactic Nuclei |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2406.03259 |