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Analysis of EUV, Microwave, and Magnetic Field Observations of Solar Plage

Published online by Cambridge University Press:  12 April 2016

J W Brosius
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
J M Davila
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
H P Jones
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
W T Thompson
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
R J Thomas
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
G D Holman
Affiliation:
NASA Goddard Space Flight Center, Code 682, Greenbelt, MD 20771
S M White
Affiliation:
Astronomy Program, University of Maryland, College Park, MD 20742
N Gopalswamy
Affiliation:
Astronomy Program, University of Maryland, College Park, MD 20742
M R Kundu
Affiliation:
Astronomy Program, University of Maryland, College Park, MD 20742

Abstract

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We obtained simultaneous images of solar plage on 7 May 1991 with Goddard Space Flight Center’s Solar EUV Rocket Telescope and Spectrograph (SERTS), the Very Large Array (VLA), and the NASA/NSO spectromagnetograph at Kitt Peak. Using intensity ratios of Fe XVI to Fe XV emission lines, we find that the coronal plasma temperature is 2.5 ± 0.3 ×lO6 K throughout the region. The column emission measure ranges from 2.6 × 1027 to 1.3 × 1028 cm−5. The calculated structure and intensity of the 20 cm wavelength thermal bremsstrahlung emission from the hot plasma observed by SERTS is quite similar to the observed structure and intensity of the 20 cm microwave emission observed by the VLA. Using the revised coronal iron abundance of Meyer (1991, 1992), we find no evidence for either cool absorbing plasma or for contributions from thermal gyroemission. Combining the observed microwave polarization and the SERTS plasma parameters, we calculate a map of the coronal longitudinal magnetic field. The resulting values, ~ 30 – 60 Gauss, are comparable to extrapolated values of the potential field at heights of 5,000 and 10,000 km.

Type
Session 5. Fields in the Chromosphere and Corona
Copyright
Copyright © Astronomical Society of the Pacific 1993

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