Long Characteristics versus Short Characteristics in 3D Radiative Transfer Simulations of Polarized Radiation
- 1 May 2021
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 912 (1), 63
- https://doi.org/10.3847/1538-4357/abec6b
Abstract
We compare maps of scattering polarization signals obtained from three-dimensional (3D) radiation transfer calculations in a magnetoconvection model of the solar atmosphere using formal solvers based on the “short characteristics” (SC) and the “long characteristics” (LC) methods. The SC method requires less computational work, but it is known to introduce spatial blurring in the emergent radiation for inclined lines of sight. For polarized radiation this effect is generally more severe due to it being a signed quantity and to the sensitivity of the scattering polarization to the model’s inhomogeneities. We study the differences in the polarization signals of the emergent spectral line radiation calculated with such formal solvers. We take as a case study already published results of the scattering polarization in the Sr i 4607 Å line obtained with the SC method, demonstrating that in high-resolution grids it is accurate enough for that type of study. In general, the LC method is the preferred one for accurate calculations of the emergent radiation, which is the reason why it is now one of the options in the public version of the 3D radiative transfer code PORTA.Funding Information
- EC ∣ European Research Council (742265)
This publication has 12 references indexed in Scilit:
- Radiation hydrodynamics in simulations of the solar atmosphereLiving Reviews in Solar Physics, 2020
- A Novel Investigation of the Small-scale Magnetic Activity of the Quiet Sun via the Hanle Effect in the Sr i 4607 Å LineThe Astrophysical Journal, 2018
- DELO-BEZIER FORMAL SOLUTIONS OF THE POLARIZED RADIATIVE TRANSFER EQUATIONThe Astrophysical Journal, 2013
- SCATTERING POLARIZATION AND HANLE EFFECT IN STELLAR ATMOSPHERES WITH HORIZONTAL INHOMOGENEITIESThe Astrophysical Journal, 2011
- Polarization in Spectral LinesPublished by Springer Science and Business Media LLC ,2004
- Short characteristic integration of radiative transfer problems: Formal solution in two-dimensional slabsJournal of Quantitative Spectroscopy and Radiative Transfer, 1988
- Two-dimensional isotropic scattering in a semi-infinite mediumJournal of Quantitative Spectroscopy and Radiative Transfer, 1978
- Two-dimensional radiative transfer. I - Planar geometryThe Astrophysical Journal, 1978
- The Formation of Resonance Lines in Multidimensional Media. III. Interpolation Functions, Accuracy, and StabilityThe Astrophysical Journal, 1973
- The Formation of Resonance Lines in Multidimensional Media. II. Radiation Operators and Their Numerical RepresentationThe Astrophysical Journal, 1973