相关论文: The uncombed penumbra

A theoretical sunspot model is provided including magnetic suppression of the diffusivities and also a strong stratification of density and temperature. Heat diffusion alone with given magnetic field and zero mean flow only produces (after…

Solar prominences and filaments (prominences projected against the solar disk) exhibit a large variety of fine structures which are well observed down to the resolution limit of ground-based telescopes. We describe the morphological aspects…

We investigate sharp structures visible in solar magnetic field tracers. It is shown that the sunspot magnetic boundaries do not coincide with the photometric ones. Moreover, there is no clear boundary of the magnetic field in the vicinity…

High resolution spectropolarimetric observations of 3 sunspots taken with Hinode demonstrate the existence of supersonic downflows at or close to the umbra-penumbra boundary which have not been reported before. These downflows are confined…

I derived a geometrical model of the penumbral magnetic field topology from an uncombed inversion setup that aimed at reproducing the NCP of simultaneous spectra in near-IR (1.56 mu) and VIS (630 nm) spectral lines. I inverted the spectra…

Context. A significant part of the penumbral magnetic field returns below the surface in the very deep photosphere. For lines in the visible, a large portion of this return field can only be detected indirectly by studying its imprints on…

High-resolution observations of the solar photosphere have recently revealed the presence of elongated filamentary bright structures inside sunspot umbrae. These features, which have been called umbral filaments (UFs), differ in morphology,…

We investigate sharply outlined features recorded in solar magnetic field tracers. It is shown that the magnetic boundaries of a sunspot do not coincide with the photometric ones. Moreover, there is no clear magnetic boundary around…

We present a method to study the penumbral fine structure using data obtained by the spectropolarimeter onboard HINODE. For the first time, the penumbral filaments can be considered as resolved in spectropolarimetric measurements. This…

The Solar Optical Telescope onboard Hinode revealed the fine-scale structure of the Evershed flow and its relation to the filamentary structures of the sunspot penumbra. The Evershed flow is confined in narrow channels with nearly…

Solar magnetic fields are generated in the solar interior and pop up at the solar surface to form active regions. As the magnetic field appears on the surface, it forms various structures like small magnetic elements, pores, and sunspots.…

A sunspot emanates from a growing pore or protospot. In order to trigger the formation of a penumbra, large inclinations at the outskirts of the protospot are necessary. The penumbra develops and establishes by colonising both umbral areas…

Inversions of spectropolarimetric observations of penumbral filaments deliver the stratification of different physical quantities in an optical depth scale. However, without establishing a geometrical height scale their three-dimensional…

In this review we give an overview about the current state-of-knowledge of the magnetic field in sunspots from an observational point of view. We start by offering a brief description of tools that are most commonly employed to infer the…

We investigate the thermal topology in a super-penumbral canopy by determining the 3D thermal structure of an active region. We derive the temperature stratifications in the active region by an inversion of the Ca II IR line at 854.2 nm,…

Numerical simulations have by now revealed that the fine scale structure of the penumbra in general and the Evershed effect in particular is due to overturning convection, mainly confined to gaps with strongly reduced magnetic field…

Advances in instrumentation have made it possible to study sunspots with unprecedented detail. New capabilities include imaging observations at a resolution of 0.1" (70 km on the sun), spectroscopy at ~0.2", and simultaneous…

We employ high-spatial resolution spectropolarimetric observations from the Solar Optical Telescope on-board the Hinode spacecraft to investigate the fine structure of the penumbral magnetic fields. The Stokes vector of two neutral iron…

Discovered in 1909 the Evershed effect represents strong mass outflows in sunspot penumbra, where the magnetic field of sunspots is filamentary and almost horizontal. These flows play important role in sunspots and have been studied in…

A light bridge is a prominent structure commonly observed within a sunspot. Its presence usually triggers a wealth of dynamics in a sunspot, and has a lasting impact on sunspot evolution. However, the fundamental structure of light bridges…