Systematic radial flows in the chromosphere, transition region, and corona of the quiet sun
1991; IOP Publishing; Volume: 372; Linguagem: Inglês
10.1086/170014
ISSN1538-4357
AutoresDonald M. Hassler, G. J. Rottman, F. Q. Orrall,
Tópico(s)Solar Radiation and Photovoltaics
Resumoview Abstract Citations (66) References (43) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Systematic Radial Flows in the Chromosphere, Transition Region, and Corona of the Quiet Sun Hassler, Donald M. ; Rottman, Gary J. ; Orrall, Frank Q. Abstract An observational study of the systematic radial flows representative of the quiet sun's chromosphere, transition region, and corona is presented. A sounding rocket experiment (July 27, 1987) obtained high-resolution EUV spectra along a solar diameter with spatial resolution of 20 x 20 arcsec. The center-to-limb behavior of four representative lines (Si II 1533 A, Fe II 1563 A, C IV 1548 A, Ne VIII 770 A formed at different heights in the solar atmosphere is discussed. Assuming that horizontal motions cancel statistically so that the line-of-sight velocity approaches zero at the limb, the net radial downflow is approximately 7.5 + or - 1.0 km/s for C IV, 2.7 + or - 1.5 km/s for Fe II 1563 A, and upper limits of 0 + or - 1.2 km/s and 0 + or - 4 km/s for Si II and Ne VIII, respectively. The absolute wavelengths of each emission line were determined by direct comparison with wavelengths of known platinum lines generated by an inflight calibration lamp. The assumption of line-of-sight velocity approaching zero at the limb is then tested by comparing the wavelengths with recently published laboratory rest wavelengths of the solar emission lines. Publication: The Astrophysical Journal Pub Date: May 1991 DOI: 10.1086/170014 Bibcode: 1991ApJ...372..710H Keywords: Chromosphere; Radial Flow; Solar Corona; Solar Spectra; Extreme Ultraviolet Radiation; Line Spectra; Solar Activity; Spectrum Analysis; Ultraviolet Spectra; Solar Physics; SUN: ATMOSPHERIC MOTIONS; SUN: CHROMOSPHERE; SUN: CORONA; SUN: TRANSITION REGION; ULTRAVIOLET: SPECTRA full text sources ADS |
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