Penumbral models in the light of Hinode spectropolarimetric observations

TL;DR

This study compares penumbral models with Hinode spectropolarimetric data, revealing that dark filaments in the outer penumbra have stronger flows and more inclined magnetic fields, challenging the field-free gappy penumbra scenario.

Contribution

It provides the first detailed plasma stratification analysis of penumbral filaments using Hinode data, testing and challenging existing penumbral models.

Findings

Dark filaments in the outer penumbra have stronger flows.

Higher magnetic field inclination correlates with darker filaments.

Results challenge the field-free gappy penumbra model.

Abstract

The realism of current models of the penumbra is assessed by comparing their predictions with the plasma properties of penumbral filaments as retrieved from spectropolarimetric observations. The spectropolarimeter onboard Hinode allows us to distinguish for the first time the fine structure of the penumbra. Therefore, we can use one-component inversions to obtain the stratifications of plasma parameters in each pixel. The correlations between the plasma parameters and the continuum intensity are studied. We find that, in the outer penumbra, the stronger flows and higher values of magnetic field inclination tend to be located in dark filaments. This finding does not seem to be compatible with the scenario of a field-free gappy penumbra.