Coronal Plasma Motions near Footpoints of Active Region Loops Revealed from Spectroscopic Observations with Hinode EIS

−1 and enhanced nonthermal velocities have been found near the footpoints of the active region loops assuming a single Gaussian approximation for the emission-line profiles. When the same part of the active region is observed near the limb, both upflows and enhanced nonthermal velocities essentially decrease. There is a strong correlation between Doppler velocity and nonthermal velocity. Significant deviations from a single Gaussian profile are found in the blue wing of the line profiles for the upflows. These suggest that there are unresolved high-speed upflows. We discuss the implications for coronal heating mechanisms. -->
ISSN: 1538-4357
0004-637X
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_________::5fb25bbad8d2f75aafef92c386d3ff7f
https://doi.org/10.1086/588252
Rights: OPEN
Přírůstkové číslo: edsair.doi...........5fb25bbad8d2f75aafef92c386d3ff7f
Autor: Louise K. Harra, Hirohisa Hara, George A. Doschek, J. Leonard Culhane, John T. Mariska, Tetsuya Watanabe, Peter R. Young
Rok vydání: 2008
Předmět:
Zdroj: The Astrophysical Journal. 678:L67-L71
ISSN: 1538-4357
0004-637X
Popis: The solar active region 10938 has been observed from the disk center to the west limb with the Hinode EUV Imaging Spectrometer. In the disk-center observation, subsonic upflow motions of tens of km s -->−1 and enhanced nonthermal velocities have been found near the footpoints of the active region loops assuming a single Gaussian approximation for the emission-line profiles. When the same part of the active region is observed near the limb, both upflows and enhanced nonthermal velocities essentially decrease. There is a strong correlation between Doppler velocity and nonthermal velocity. Significant deviations from a single Gaussian profile are found in the blue wing of the line profiles for the upflows. These suggest that there are unresolved high-speed upflows. We discuss the implications for coronal heating mechanisms.
Databáze: OpenAIRE
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