Some Consequences of an Uncombed and Inhomogeneous Penumbra

Solanki, S. K.; Montavon, C. A. P.

doi:10.1007/978-94-011-1188-1_21

Cited by 2 publications

(2 citation statements)

References 8 publications

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“…The idea of elevated penumbral filaments has already been mentioned by Moore (1981), based on the investigation of sunspot photographs. Solanki & Montavon (1994) used a similar picture as a possible explanation for the brightness variation at the umbra-penumbra border, but, to our knowledge, no observations have been carried out in this respect.…”

Section: Introductionmentioning

confidence: 99%

On the geometry of sunspot penumbral filaments

Schmidt

Fritz

2004

A&A

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Abstract. We investigate the center-to-limb variation of the brightness of the penumbrae of sunspots. The analysis includes narrow-band and broad-band continuum images of about 80 sunspots observed with the Vacuum Tower Telescope on Tenerife and with the Transition Region And Coronal Explorer (TRACE). We find that the azimuthal intensity variation depends on the viewing angle, i.e. on the position of the spot on the solar disk. With increasing viewing angle, the average intensity remains almost constant on the center side and on the limb side of the spot, but increases in the lateral parts. This is explained by the existence of elevated bright filaments that, when observed from the side and at increasing viewing angle, more and more hide the dark and deeper lying background. In addition to this azimuthal intensity modulation, we observe an enhanced brightness on the limb-side penumbra for large viewing angles.

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Section: Introductionmentioning

confidence: 99%

On the geometry of sunspot penumbral filaments

Schmidt

Fritz

2004

A&A

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“…This is however common for V spectra along apparent neutral lines (see for example Skumanich and Lites, 1991;Ss Almeida and Lites, 1992;Riiedi et al, 1992b). Since the observed region lies outside sunspots (at the edge of a pore without a visible penumbra) it is likely that two magnetic components with similar field strengths but with opposite magnetic polarities and different flow velocities coexist in the same resolution element (within penumbrae V profiles of the same general shape can be produced by a single magnetic component: Ss Almeida and Lites, 1992;Solanki et al, 1994). The discontinuity in the synthetic profiles around A = 5250.5/~ is due to an overlap of the selected spectral wavelength ranges over which these two lines are synthesized.…”

Section: Examples Of Inversions With a 3-component Modelmentioning

confidence: 99%

Inversion of Stokes vector profiles in terms of a 3-component model

Bernasconi¹,

Solanki²

1996

Sol Phys

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Various spectropolarimetric observations show pecuhar Stokes profiles that reveal the coexistence of at least two magnetic components in the same resolution element. An example is given by observations of the full Stokes vector in a complex active region performed with the ZIMPOL I Stokes polarimeter. In order to deduce the physical parameters of the observed regions from such measured profiles, we have extended an existing inversion code, so that it can now fit the data with models composed of up to three different atmospheric components. Two of these components are magnetic and may possess different field strengths, field geometries, temperature stratifications, and velocity fields. The third component describes the field free atmosphere surrounding the magnetic features.The so extended inversion code has then been apphed to the ZIMPOL I data. In this paper we present and discuss sample fits. The code is able to reproduce the observed complex Stokes profiles with good accuracy and provides physical parameters for both of the coexisting magnetic atmospheres. Inversion tests with a 2-eomponent model (with one magnetic and one non-magnetic component) apphed to the same profiles do not reproduce the measurements sufficiently well.

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Some Consequences of an Uncombed and Inhomogeneous Penumbra

Cited by 2 publications

References 8 publications

On the geometry of sunspot penumbral filaments

On the geometry of sunspot penumbral filaments

Inversion of Stokes vector profiles in terms of a 3-component model

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