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Author Schmelz, J. T. ♦ Nasraoui, K. ♦ Saar, S. H. ♦ Kashyap, V. L. ♦ Weber, M. A. ♦ DeLuca, E. E. ♦ Golub, L.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATHEMATICAL METHODS AND COMPUTING ♦ ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ALGORITHMS ♦ GAMMA RADIATION ♦ ITERATIVE METHODS ♦ MATHEMATICAL SOLUTIONS ♦ MONTE CARLO METHOD ♦ SOLAR CORONA ♦ SPECTROMETERS ♦ SUN ♦ TELESCOPES ♦ TEMPERATURE DISTRIBUTION ♦ THERMODYNAMIC PROPERTIES ♦ ULTRAVIOLET RADIATION ♦ X RADIATION ♦ ATMOSPHERES ♦ CALCULATION METHODS ♦ ELECTROMAGNETIC RADIATION ♦ IONIZING RADIATIONS ♦ MAIN SEQUENCE STARS ♦ MATHEMATICAL LOGIC ♦ MEASURING INSTRUMENTS ♦ PHYSICAL PROPERTIES ♦ RADIATIONS ♦ SOLAR ATMOSPHERE ♦ STARS ♦ STELLAR ATMOSPHERES ♦ STELLAR CORONAE
Abstract Data from the X-Ray Telescope (XRT) and the EUV Imaging Spectrometer (EIS) on the Japanese/USA/UK Hinode spacecraft were used to investigate the spatial and thermal properties of an isolated quiescent coronal loop. We constructed differential emission measure (DEM) curves using Monte Carlo based, iterative forward fitting algorithms. We studied the loop as a whole, in segments, in transverse cuts, and point-by-point, always with some form of background subtraction, and find that the loop DEM is neither isothermal nor extremely broad, with approximately 96% of the EM between 6.2 {<=}log T{<=} 6.7, and an EM-weighted temperature of log T = 6.48 {+-} 0.16. We find evidence for a gradual change in temperature along the loop, with log T increasing only by {approx}0.1 from the footpoints to the peak. The combine XRT-EIS data set does a good job of constraining the temperature distribution for coronal loop plasma. Our studies show that the strong constraints at high and low temperatures provided by the combined data set are crucial for obtaining reasonable solutions. These results confirm that the observations of at least some loops are not consistent with isothermal plasma, and therefore cannot be modeled with a single flux tube and must be multi-stranded.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-11-10
Publisher Place United States
Journal Astrophysical Journal
Volume Number 723
Issue Number 2


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