## Theoretical study of the polarization by resonance scattering of the H line in spicules
One currently observes spicules in the H line, the underlying photospheric radiation being scattered by the matter of the spicules. In this paper we solve the equations of statistical equilibrium for a hydrogen atom having an ensemble velocity and being illuminated by the photospheric radiation field. This leads us to the determination of the Stokes parameters of the radiation diffused by the spicule towards the observer. The calculations include fine structure effects, limb darkening and depolarization by isotropic collisions. One obtains the linear polarization degree as well as the rotation of the polarization plane as a function of the ascending velocity of matter in spicules.
## Contents- 1. Introduction
- 2. The H absorption profile
- 3. The general solution
- 4. Limits of the polarization degree
- 5. The effect of collisions
- 6. Conclusion
- Acknowledgements
- Appendix A
- References
© European Southern Observatory (ESO) 1998 Online publication: April 28, 1998 |