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Plasma properties and stokes profiles during the lifetime of a photospheric magnetic bright point

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journal contribution
posted on 2014-05-01, 00:00 authored by R L Hewitt, Sergiy ShelyagSergiy Shelyag, M Mathioudakis, F P Keenan
Aims. In this paper we aim to investigate the evolution of plasma properties and Stokes parameters in photospheric magnetic bright points using 3D magneto-hydrodynamical simulations and radiative diagnostics of solar granulation. Methods. Simulated time-dependent radiation parameters and plasma properties were investigated throughout the evolution of a bright point. Synthetic Stokes profiles for the FeI 630.25 nm line were calculated, which also allowed the evolution of the Stokes-I line strength and Stokes-V area and amplitude asymmetries to be investigated. Results. Our results are consistent with theoretical predictions and published observations describing convective collapse, and confirm this as the bright point formation process. Through degradation of the simulated data to match the spatial resolution of SOT, we show that high spatial resolution is crucial for the detection of changing spectro-polarimetric signatures throughout a magnetic bright point's lifetime. We also show that the signature downflow associated with the convective collapse process tends towards zero as the radiation intensity in the bright point peaks, because of the magnetic forces present restricting the flow of material in the flux tube.

History

Journal

Astronomy and astrophysics

Volume

565

Article number

A84

Pagination

1 - 13

Publisher

EDP Sciences

Location

London, Eng.

ISSN

0004-6361

eISSN

1432-0746

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2014, ESO