Origins of the Solar Wind
Abstract
This paper presented the differential emission measure analysis of SUMER observations of a coroner streamer. We found that: The coroner streamer is isothermal at all heights. This suggests that the loops comprising the streamer must have very flat temperature profiles. The coroner streamer is "overdense" relative to the predictions of hydrostatic equilibrium at most heights. At the lowest heights the streamer is actually "underdense". The SUMER temperature measurements are not consistent with those derived from simultaneous SXT observations. SXT indicates systematically higher temperatures as well as a strong temperature gradient. These SUMER measurements yield somewhat lower temperatures and no gradient in the temperature with height. Previous work has suggested that there may be a hot component to the streamer that is preferentially observed with SXT. Our analysis shows that high temperature emission lines would be observed with SUMER if this were true and thus discounts this possibility. We suggested that scattered light in SXT might produce spurious temperature measurements. The temperature and density structure of this coroner streamer are very similar to "TRACE" active region loops (flat temperature profiles, overdense relative to uniform heating, and relatively cool temperatures).
- Publication:
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NASA STI/Recon Technical Report N
- Pub Date:
- May 2002
- Bibcode:
- 2002STIN...0251137W
- Keywords:
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- Solar Wind;
- Temperature Profiles;
- High Temperature;
- Temperature Gradients;
- Emission Spectra;
- Temperature Measurement;
- Heating;
- Hydrostatics;
- Solar Physics