| 词条 | Neupert effect |
| 释义 |
The Neupert Effect refers to an empirical tendency for high-energy ('hard') X-ray emission to coincide temporally with the rate of rise of lower-energy ('soft') X-ray emission of a solar flare.[1] Here 'hard' and 'soft' mean above and below an energy of about 10 keV to solar physicists, though in non-solar X-ray astronomy one typically sets this boundary at a lower energy. This effect gets its name from NASA solar physicist and spectroscopist Werner Neupert, who first documented a related correlation (the integral form) between microwave (gyrosynchrotron) and soft X-ray emissions in 1968.[2] The standard interpretation is that the accumulated energy injection associated with the acceleration of non-thermal electrons (which produce the hard X-rays via non-thermal bremsstrahlung) release energy in the lower solar atmosphere (the chromosphere); this energy then leads to thermal (soft X-ray) emission as the chromospheric plasma heats and expands into the corona.[1] The effect is very common, but does not represent an exact relationship and is not observed in all solar flares.[3] See also{{Portal|Solar System|Astronomy|Star}}{{cmn|colwidth=15em|
}} References1. ^1 {{cite journal|last1=Veronig|first1=Astrid|last2=Brown|first2=John|last3=Dennis|first3=Brian|last4=Schwartz|first4=Richard|last5=Sui|first5=Linhui|last6=Tolbert|first6=Kimberley|title=Physics of the Neupert Effect: Estimates of the Effects of Source Energy, Mass Transport, and Geometry Using RHESSI and GOES Data|journal=The Astrophysical Journal|date=March 2005|volume=621|issue=1|pages=482–497|doi=10.1086/427274|url=http://iopscience.iop.org/0004-637X/621/1/482|accessdate=8 February 2015|bibcode=2005ApJ...621..482V}} {{astronomy-stub}}2. ^{{cite journal|last1=Neupert|first1=Werner|title=Comparison of Solar X-Ray Line Emission with Microwave Emission during Flares|journal=Astrophysical Journal|date=July 1968|volume=153|page=L59|doi=10.1086/180220|bibcode=1968ApJ...153L..59N}} 3. ^{{cite web|last1=McTiernan|first1=Jim|title=The Neupert Effect as a Function of Temperature|url=https://www.ssl.berkeley.edu/~jimm/neupert.html|accessdate=8 February 2015}} 1 : X-rays |
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