Abstract Details
| Name: Sowmya Krishnamurthy Affiliation: Max Planck Institute for Solar System Research Conference ID: ASI2018_1723 Title : Scattering polarization with Paschen--Back effect as a tool to diagnose the magnetic structuring of the solar atmosphere Authors and Co-Authors : Nagendra K. N. Indian Institute of Astrophysics, Bangalore. Abstract Type : Thesis Abstract Category : Thesis Abstract : When the magnetic field is sufficiently strong, it produces a splitting whose pattern is very different from that expected for the Zeeman effect. Apart from completely splitting the atomic lines, it also causes the magnetic substates of different atomic states to interfere. Such an effect of the magnetic field is called Paschen--Back effect. It acts in those domains of field strength that are not accessible through the standard techniques based on the Zeeman effect. Due to the different magnetic field strength regimes in which they operate, the Hanle, Zeeman, and Paschen--Back effects complement one another. The role played by the Paschen--Back effect in shaping the polarization profiles of the solar spectral lines needs to be understood in order to explore the possibility of using the Paschen--Back effect as a diagnostic tool for solar magnetic fields. To this end, in my PhD thesis, we developed the scattering theory of Paschen--Back effect in atomic states by accounting for the redistribution in the frequencies of the photons due to Doppler shift and applied it to analyze the polarization profiles of diagnostically important solar spectral lines. This study is an important step forward in understanding the effects of strong magnetic fields and their manifestation in the polarized line radiation emerging from the solar (or stellar) atmosphere. I shall discuss the signatures of Paschen--Back effect in polarization that we identified and their usefulness for studying magnetic fields on the Sun. |