A Novel Investigation of the Small-scale Magnetic Activity of the Quiet Sun via the Hanle Effect in the Sr I 4607 angstrom Line

0494599 - ASÚ 2019 RIV US eng J - Článek v odborném periodiku
Aleman, T. P. - Bueno, J.T. - Štěpán, Jiří - Shchukina, N.
A Novel Investigation of the Small-scale Magnetic Activity of the Quiet Sun via the Hanle Effect in the Sr I 4607 angstrom Line.
Astrophysical Journal. Roč. 863, č. 2 (2018), č. článku 164. ISSN 0004-637X. E-ISSN 1538-4357
Grant CEP: GA ČR(CZ) GA16-16861S
Institucionální podpora: RVO:67985815
Klíčová slova: polarization * radiative transfer * scattering
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 5.580, rok: 2018

We present the results of a novel investigation of the Hanle effect in this resonance line based on 3D radiative transfer calculations in a high-resolution magneto-convection model having most of the convection zone magnetized close to the equipartition and a surface mean field strength Bn approximate to 170 G. The Hanle effect produced by the model's magnetic field depolarizes the zero-field scattering polarization signals significantly, to the extent that the center-to-limb variation (CLV) of the calculated spatially averaged polarization amplitudes is compatible with the observations. The standard deviation of the horizontal fluctuations of the calculated scattering polarization signals is very sensitive to the model's magnetic field, and we find that the predicted spatial variations are sufficiently sizable so as to be able to detect them, especially with the next generation of solar telescopes. We find that at all on-disk positions, the theoretical scattering polarization signals are anticorrelated with the continuum intensity. To facilitate reaching new observational breakthroughs, we show how the theoretically predicted polarization signals and spatial variations are modified when deteriorating the signal-to-noise ratio and the spectral and spatial resolutions of the simulated observations.
Trvalý link: http://hdl.handle.net/11104/0287712