| タイトル | Widespread Nanoflare Variability Detected with Hinode/XRT in a Solar Active Region |
| 本文（外部サイト） | http://hdl.handle.net/2060/20110008000 |
| 著者（英） | Terzo, Sergio; Reale, Fabio; Klimchuk, James A.; Miceli, Marco; Kano, Ryouhei; Tsuneta, Saku |
| 著者所属（英） | NASA Goddard Space Flight Center |
| 発行日 | 2011-01-01 |
| 言語 | eng |
| 内容記述 | It is generally agreed that small impulsive energy bursts called nanoflares are responsible for at least some of the Sun s hot corona, but whether they are the explanation for most of the multi-million degree plasma has been a matter of ongoing debate. We here present evidence that nanoflares are widespread in an active region observed by the X-Ray Telescope on-board the Hinode mission. The distributions of intensity fluctuations have small but important asymmetries, whether taken from individual pixels, multi-pixel subregions, or the entire active region. Negative fluctuations (corresponding to reduced intensity) are greater in number but weaker in amplitude, so that the median fluctuation is negative compared to a mean of zero. Using Monte Carlo simulations, we show that only part of this asymmetry can be explained by Poisson photon statistics. The remainder is explainable with a tendency for exponentially decreasing intensity, such as would be expected from a cooling plasma produced, e.g., from a nanoflare. We suggest that nanoflares are a universal heating process within active regions. |
| NASA分類 | Solar Physics |
| 権利 | Copyright, Distribution as joint owner in the copyright |
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