Dynamics of the solar atmosphere above a pore with a light bridge

Abstract

Context: Solar pores are small sunspots lacking a penumbra that have a prevailing vertical magnetic field component. They can include light bridges at places with locally reduced magnetic field. Like sunspots, they exhibit a wide range of oscillatory phenomena. Aims: A large isolated pore with a light bridge (NOAA 11005) is studied to obtain characteristics of a chromospheric filamentary structure around the pore, to analyse oscillations and waves in and around the pore, and to understand the structure and brightness of the light bridge. Methods: Spectral imaging observations in the line Ca II 854.2 nm and complementary spectropolarimetry in Fe I lines, obtained with the DST/IBIS spectrometer and HINODE/SOT spectropolarimeter, were used to measure photospheric and chromospheric velocity fields, oscillations, waves, the magnetic field in the photosphere, and acoustic energy flux and radiative losses in the chromosphere. Results: The chromospheric filamentary structure around the pore has all important characteristics of a superpenumbra: it shows an inverse Evershed effect and running waves, and has a similar morphology and oscillation character. The granular structure of the light bridge in the upper photosphere can be explained by radiative heating. Acoustic waves leaking up from the photosphere along the inclined magnetic field in the light bridge transfer enough energy flux to balance the total radiative losses of the light-bridge chromosphere. Conclusions: The presence of a penumbra is not a necessary condition for the formation of a superpenumbra. The light bridge is heated by radiation in the photosphere and by acoustic waves in the chromosphere.

14 pages, 14 figures, 3 tables, accepted for publication in Astrononomy & Astrophysics

References in corpus (5)

• The Solar Optical Telescope for the Hinode Mission: An Overview
• The solar chromosphere at high resolution with IBIS. I. New insights from the Ca II 854.2 nm line
• The origin of the reversed granulation in the solar photosphere
• Evaluating local correlation tracking using CO5BOLD simulations of solar granulation
• The photospheric environment of a solar pore with light bridge

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• Three-dimensional magnetic structure of a sunspot: comparison of the photosphere and upper chromosphere
• A novel approach to identify resonant MHD wave modes in solar pores and sunspot umbrae: $B-\omega$ analysis
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• Oscillations In The Line-of-Sight Magnetic Field Strength In A Pore Observed By The GREGOR Infrared Spectrograph (GRIS)
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• Spectropolarimetric investigation of magnetohydrodynamic wave modes in the photosphere: First results from PHI on board Solar Orbiter
• Does H$\alpha$ Stokes~$V$ profiles probe the chromospheric magnetic field? An observational perspective
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• Chromospheric Heating by Acoustic Waves Compared to Radiative Cooling: II -- Revised Grid of Models