Trujillo Bueno, J. and Manso Sainz, R. (2002) Remote sensing of chromospheric magnetic fields via the Hanle and Zeeman effects. Il nuovo cimento C, 25 (5\6). pp. 783-796. ISSN 1826-9885
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Abstract
The only way to obtain reliable empirical information on the intensity and topology of the weak magnetic fields of the “quiet” solar chromosphere is via the measurement and rigorous physical interpretation of weak polarization signals in chromospheric spectral lines. The observed Stokes profiles reported here are due to the Hanle and Zeeman effects operating in a weakly magnetized plasma that is ina state far from local thermodynamic equilibrium. The physical origin of their “enigmatic” linear polarization Q and U components is the existence of atomic polarization in their metastable lower levels, which permits the actionof a dichroism mechanism that has nothing to do with the transverse Zeeman effect. It is also pointed out that the population imbalances and coherences among the Zeeman sublevels of such long-lived atomic levels cannot only survive in the presence of horizontal magnetic fields having intensities in the gauss range, but also produce very significant polarization signals. Finally, it is shown how the most recent developments in the observation and theoretical modelling of weak polarization signals are facilitating fundamental new advances in our ability to investigate the magnetism of the outer solar atmosphere via spectropolarimetry.
| Item Type: | Article |
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| Additional Information: | Paper presented at the International Meeting on THEMIS and the New Frontiers of Solar Atmosphere Dynamics, Rome, Italy, March 19-21, 2001. |
| Uncontrolled Keywords: | Solar physics ; Radiation mechanisms; polarization ; Radiative transfer; scattering ; Level crossing and optical pumping |
| Subjects: | 500 Scienze naturali e Matematica > 550 Scienze della Terra > 551 Geologia, Idrologia, Meteorologia > 551.5 Meteorologia (Classificare qui l'atmosfera) (Classificare la previsione e le previsioni di specifici fenomeni meteorologici in 551.64; classificare la Micrometeorologia in 551.66) > 551.52 Termodinamica, interazioni atmosferiche con la superficie terrestre, temperature, radiazioni > 551.527 Radiazioni (per fenomeni ottici, vedi 551.565) > 551.5271 Radiazione solare |
| Depositing User: | Marina Spanti |
| Date Deposited: | 12 Mar 2020 17:22 |
| Last Modified: | 12 Mar 2020 17:22 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/15081 |
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