Conferencia
Abstract:
An observing campaign coordinated between ground based and SOHO instruments has been planned to obtain simultaneous spectroheliograms of the same area in several spectral lines. The chromospheric lines Ca II K, Hα and Na I D, as well as the He I 10830, 5876, 584 and He II 304 Å lines, have been observed. These observations allow us to build semi-empirical models of the chromosphere and low transition region of an active region, taking into account the photoionizing photons impinging on it. We obtained a model that matches very well all the observed line profiles, using the standard value of the He abundance ([He]=0.1). We studied the influence of the coronal radiation on the computed helium lines and found that, even in an active region, the incident coronal radiation has a limited effect on the UV He lines, while it results of fundamental importance for the D3 and 10830 lines. Finally, we built two more models assuming values of the He abundance [He]=0.07 and 1.5, only in the region where the temperatures are larger than 10000 K and found that the observations can still be well reproduced in both cases. This implies that, to choose between different values of [He], it is necessary to constrain the transition region with different observables, independent of the He lines.
Registro:
| Documento: | Conferencia |
| Título: | Helium line formation in a solar active region |
| Autor: | Mauas, P.J.D.; Andretta, V.; Falchi, A.; Falciani, R.; Teriaca, L.; Cauzzi, G.; Favata F.; Hussain G.A.J.; Battrick B. |
| Ciudad: | Hamburg |
| Filiación: | Instituto de Astronomía y Física del Espacio, CC. 67, Suc. 28, 1428 Buenos Aires, Argentina INAF, Osservatorio Astronomico di Capodimonte, Salita Moiariello 16, 80131 Napoli, Italy INAF, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, 50125 Firenze, Italy Dipartimento di Astronomia e Scienza dello Spazio, Università di Firenze, Largo Fermi 5, 50125 Firenze, Italy Max-Planck-Institut für Sonnensystemforschung, Max-Planck-Str. 2, 37191 Katlenburg-Lindau, Germany |
| Palabras clave: | Sun: abundances; Sun: activity; Sun: Helium; Infrared radiation; Photoionization; Photons; Plasmas; Scanning electron microscopy; Solar energy; Sun; Ultraviolet radiation; Spectroheliograms; Sun: abundances; Sun: activity; Sun: Helium; Helium |
| Año: | 2005 |
| Número: | 560 II |
| Página de inicio: | 811 |
| Página de fin: | 814 |
| Título revista: | 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun |
| Título revista abreviado: | Eur Space Agency Spec Publ ESA SP |
| ISSN: | 03796566 |
| CODEN: | ESPUD |
| Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n560II_p811_Mauas |
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Citas:
---------- APA ----------
Mauas, P.J.D., Andretta, V., Falchi, A., Falciani, R., Teriaca, L., Cauzzi, G., Favata F.,..., Battrick B. (2005) . Helium line formation in a solar active region. 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun(560 II), 811-814.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n560II_p811_Mauas [ ]
---------- CHICAGO ----------
Mauas, P.J.D., Andretta, V., Falchi, A., Falciani, R., Teriaca, L., Cauzzi, G., et al. "Helium line formation in a solar active region" . 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, no. 560 II (2005) : 811-814.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n560II_p811_Mauas [ ]
---------- MLA ----------
Mauas, P.J.D., Andretta, V., Falchi, A., Falciani, R., Teriaca, L., Cauzzi, G., et al. "Helium line formation in a solar active region" . 13th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun, no. 560 II, 2005, pp. 811-814.Recuperado de https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n560II_p811_Mauas [ ]
---------- VANCOUVER ----------
Mauas, P.J.D., Andretta, V., Falchi, A., Falciani, R., Teriaca, L., Cauzzi, G., et al. Helium line formation in a solar active region. Eur Space Agency Spec Publ ESA SP. 2005(560 II):811-814.Available from: https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03796566_v_n560II_p811_Mauas [ ]
