Bibcode
Quintero Noda, C.; Asensio Ramos, A.; Orozco Suárez, D.; Ruiz Cobo, B.
Bibliographical reference
Astronomy and Astrophysics, Volume 579, id.A3, 13 pp.
Advertised on:
7
2015
Journal
Citations
30
Refereed citations
29
Description
Context. One of the difficulties in extracting reliable information
about the thermodynamical and magnetic properties of solar plasmas from
spectropolarimetric observations is the presence of light dispersed
inside the instruments, known as stray light. Aims: We aim to
analyze quiet Sun observations after the spatial deconvolution of the
data. We examine the validity of the deconvolution process with noisy
data as we analyze the physical properties of quiet Sun magnetic
elements. Methods: We used a regularization method that decouples
the Stokes inversion from the deconvolution process, so that large maps
can be quickly inverted without much additional computational burden. We
applied the method on Hinode quiet Sun spectropolarimetric data. We
examined the spatial and polarimetric properties of the deconvolved
profiles, comparing them with the original data. After that, we inverted
the Stokes profiles using the Stokes Inversion based on Response
functions (SIR) code, which allow us to obtain the optical depth
dependence of the atmospheric physical parameters. Results: The
deconvolution process increases the contrast of continuum images and
makes the magnetic structures sharper. The deconvolved Stokes I profiles
reveal the presence of the Zeeman splitting while the Stokes V profiles
significantly change their amplitude. The area and amplitude asymmetries
of these profiles increase in absolute value after the deconvolution
process. We inverted the original Stokes profiles from a magnetic
element and found that the magnetic field intensity reproduces the
overall behavior of theoretical magnetic flux tubes, that is, the
magnetic field lines are vertical in the center of the structure and
start to fan when we move far away from the center of the magnetic
element. The magnetic field vector inferred from the deconvolved Stokes
profiles also mimic a magnetic flux tube but in this case we found
stronger field strengths and the gradients along the line-of-sight are
larger for the magnetic field intensity and for its inclination.
Moreover, the discontinuity between the magnetic and non magnetic
environment in the flux tube gets sharper. Conclusions: The
deconvolution process used in this paper reveals information that the
smearing induced by the point spread function (PSF) of the telescope
hides. Additionally, the deconvolution is done with a low computational
load, making it appealing for its use on the analysis of large data
sets.
A copy of the IDL code is available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A3
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