A Quantitative Comparison of Observed and Theoretical Stokes Profiles of the Ca II 8542 Å Line in the Quiet Sun

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F19%3A00552725" target="_blank" >RIV/67985815:_____/19:00552725 - isvavai.cz</a>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

A Quantitative Comparison of Observed and Theoretical Stokes Profiles of the Ca II 8542 Å Line in the Quiet Sun

Popis výsledku v původním jazyce

We present an analysis of the Stokes profiles of the Ca II 8542 Å line produced by the joint action of atomic level polarization and the Hanle and Zeeman effects. We compare spectropolarimetric observations of this line in a quiet region at the solar disk centre, taken with the ZIMPOL instrument at IRSOL, with the theoretical Stokes profiles computed with the PORTA radiative transfer code using as solar model atmosphere a 3D snapshot taken from a radiation MHD simulation of an enhanced-network region. Even though the spatial sampling of the ZIMPOL observations is only 1.43 arcsec/pixel, we detect Q/I, U/I and V/I polarization signals of the order of 0.1%. The synthetic line profiles have been obtained by solving the full 3D NLTE radiative transfer problem taking into account the symmetry breaking effects due to the model's horizontal inhomogeneities and macroscopic velocity gradients. After spatial and spectral degradation, in some locations we find similar amplitudes between the observed and calculated linear polarization profiles. However, in general, the observations show stronger polarization signals than the calculated ones, a discrepancy that could be used to refine the numerical models of the quiet solar chromosphere.

Název v anglickém jazyce

A Quantitative Comparison of Observed and Theoretical Stokes Profiles of the Ca II 8542 Å Line in the Quiet Sun

Popis výsledku anglicky

We present an analysis of the Stokes profiles of the Ca II 8542 Å line produced by the joint action of atomic level polarization and the Hanle and Zeeman effects. We compare spectropolarimetric observations of this line in a quiet region at the solar disk centre, taken with the ZIMPOL instrument at IRSOL, with the theoretical Stokes profiles computed with the PORTA radiative transfer code using as solar model atmosphere a 3D snapshot taken from a radiation MHD simulation of an enhanced-network region. Even though the spatial sampling of the ZIMPOL observations is only 1.43 arcsec/pixel, we detect Q/I, U/I and V/I polarization signals of the order of 0.1%. The synthetic line profiles have been obtained by solving the full 3D NLTE radiative transfer problem taking into account the symmetry breaking effects due to the model's horizontal inhomogeneities and macroscopic velocity gradients. After spatial and spectral degradation, in some locations we find similar amplitudes between the observed and calculated linear polarization profiles. However, in general, the observations show stronger polarization signals than the calculated ones, a discrepancy that could be used to refine the numerical models of the quiet solar chromosphere.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA16-16861S" target="_blank" >GA16-16861S: Vícerozměrné modelování polarizovaných spekter vnější sluneční atmosféry</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Solar Polarization Workshop 8

ISBN

978-1-58381-939-5

ISSN

1050-3390

e-ISSN

1050-3390

Počet stran výsledku

7

Strana od-do

235-241

Název nakladatele

Astronomical Society of the Pacific

Místo vydání

San Francisco

Místo konání akce

Florence

Datum konání akce

12. 9. 2016

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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