Propagating waves in the sunspot umbra chromosphere
نویسندگان
چکیده
منابع مشابه
Direct Imaging of Fine Structure in the Chromosphere of a Sunspot Umbra
High-resolution imaging observations from the Hinode spacecraft in the Ca II H line are employed to study the dynamics of the chromosphere above a sunspot. We find that umbral flashes and other brightenings produced by the oscillation are extremely rich in fine structure, even beyond the resolving limit of our observations (0.22”). The umbra is tremendously dynamic, to the point that our time c...
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Spectropolarimetric time series data of the primary spot of active region NOAA 9448 were obtained in the Si i 10827 Å line and the He i 10830 Å multiplet with the Tenerife Infrared Polarimeter. Throughout the time series the spectrograph slit was fixed over a region covering umbra, a light bridge, penumbra, and quiet sun. We present speeds of running penumbral waves in the chromosphere, their r...
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We present conspicuous activities of plasma ejections along a light bridge of a stable and mature sunspot in NOAA 8971 on 2000 May 02. We found the ejections both in the Hα (10 K) images obtained with the Domeless Solar Telescope (DST) at Hida Observatory, and in the 171 Å (Fe ix/x, ∼106 K) images obtained with the Transition Region and Coronal Explorer (TRACE). Main characteristics of the ejec...
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Acoustic waves are generated by the convective motions in the solar convection zone. When propagating upwards into the chromosphere they reach the height where the sound speed equals the Alfvén speed and they undergo mode conversion, refraction and reflection. We use numerical simulations to study these processes in realistic configurations where the wavelength of the waves is similar to the le...
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Spatiotemporal patterns of cortical activation occur superimposed upon sensory, motor, and cognitive maps. The papers by Benucci et al. and Xu et al. in this issue of Neuron demonstrate that visual responses propagate in space and may serve to link different visual areas. This is an important step toward understanding how cortical maps relate to activation patterns, a prerequisite to understand...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2004
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20035960