TEMPORAL RELATION BETWEEN THE DISAPPEARANCE OF PENUMBRAL FINE-SCALE STRUCTURE AND EVERSHED FLOW

Journal Article · Wed Apr 20 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/731/2/84· OSTI ID:21574718

Kubo, M ^[1]; Ichimoto, K ^[2]; Lites, B W ^[3]

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1. National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan)
2. Hida Observatory, Kyoto University, Takayama, Gifu 506-1314 (Japan)
3. High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

We investigate the temporal relation between the Evershed flow, dot-like bright features (penumbral grain), the complex magnetic field structure, and dark lanes (dark core) along bright filaments in a sunspot penumbra. We use a time series of high spatial resolution photospheric intensity, vector magnetic field maps, and Doppler velocity maps obtained with the Solar Optical Telescope aboard the Hinode spacecraft. We conclude that the appearance and disappearance of the Evershed flow and penumbra grains occur at nearly the same time and are associated with changes of the inclination angle of the magnetic field from vertical to more horizontal. This supports the idea that Evershed flow is a result of thermal convection in the inclined field lines. The dark core of the bright penumbral filament also appears coincidental with the Evershed flow. However, the dark-cored bright filament survives at least for 10-20 minutes after the disappearance of the Evershed flow. The heat input into the bright filament continues even after the end of heat transfer by the Evershed flow. This suggests that local heating along the bright filament is important for maintaining its brightness, in addition to heat transfer by the Evershed flow.

• OSTI ID: 21574718
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 731; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
BRIGHTNESS
CONVECTION
ENERGY TRANSFER
FILAMENTS
HEAT TRANSFER
HEATING
INCLINATION
MAGNETIC FIELDS
MAGNETISM
MASS TRANSFER
MATHEMATICS
OPTICAL PROPERTIES
PHOTOSPHERE
PHYSICAL PROPERTIES
RESOLUTION
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SPATIAL RESOLUTION
STARSPOTS
STELLAR ACTIVITY
STELLAR ATMOSPHERES
SUNSPOTS
TOPOLOGY