Advanced Forward Modeling and Inversion of Stokes Profiles Resulting from the Joint Action of the Hanle and Zeeman Effects
Authors:
- A. Asensio RamosARA. Asensio Ramos
- J. Trujillo BuenoJBJ. Trujillo Bueno
- E. Landi Degl’innocentiEDE. Landi Degl’innocenti
- 10 August 2008
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 683 (1) , 542-565
Abstract
A big challenge in solar and stellar physics in the coming years will be to decipher the magnetism of the solar outer atmosphere (chromosphere and corona) along with its dynamic coupling with the magnetic fields of the underlying photosphere. To this end, it is important to develop rigorous diagnostic tools for the physical interpretation of spectropolarimetric observations in suitably chosen spectral lines. Here we present a computer program for the synthesis and inversion of Stokes profiles caused by the joint action of atomic level polarization and the Hanle and Zeeman effects in some spectral lines of diagnostic interest, such as those of the He I 10830 A and D_3 multiplets. It is based on the quantum theory of spectral line polarization, which takes into account all the relevant physical mechanisms and ingredients (optical pumping, atomic level polarization, Zeeman, Paschen-Back and Hanle effects). The influence of radiative transfer on the emergent spectral line radiation is taken into account through a suitable slab model. The user can either calculate the emergent intensity and polarization for any given magnetic field vector or infer the dynamical and magnetic properties from the observed Stokes profiles via an efficient inversion algorithm based on global optimization methods. The reliability of the forward modeling and inversion code presented here is demonstrated through several applications, which range from the inference of the magnetic field vector in solar active regions to determining whether or not it is canopy-like in quiet chromospheric regions. This user-friendly diagnostic tool called "HAZEL" (from HAnle and ZEeman Light) is offered to the astrophysical community, with the hope that it will facilitate new advances in solar and stellar physics.Comment: 62 pages, 19 figures, 3 tables. Accepted for publication in ApKeywords
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This publication has 42 references indexed in Scilit:
- Bayesian inversion of Stokes profilesAstronomy & Astrophysics, 2007
- The Magnetic Sensitivity of the BaiiD1 and D2 Lines of the Fraunhofer SpectrumThe Astrophysical Journal, 2007
- Line Formation Theory for the Multiterm Atom with Hyperfine Structure in a Magnetic FieldThe Astrophysical Journal, 2005
- Principal Component Analysis of the HeiD3Polarization Profiles from Solar ProminencesThe Astrophysical Journal, 2005
- Magnetic Maps of Prominences from Full Stokes Analysis of the He i D3 LineThe Astrophysical Journal, 2003
- Using DIRECT to Solve an Aircraft Routing ProblemComputational Optimization and Applications, 2002
- Spectral Lines for Polarization Measurements of the Coronal Magnetic Field. II. Consistent Treatment of the Stokes Vector for Magnetic‐Dipole TransitionsThe Astrophysical Journal, 1999
- On the Role of the Solar Corona and Transition Region in the Excitation of the Spectrum of Neutral HeliumThe Astrophysical Journal, 1997
- Complete determination of the magnetic field vector and of the electron density in 14 prominences from linear polarizaton measurements in the HeI D3 and H? linesSolar Physics, 1994
- Formation of the Solar 10830 Å Line1994