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A direct comparison between euv coronal flux and helium resonance line photon flux from soho/cds data
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | DelZanna, Giulio Andretta, V. Landi, Enrico Jordan, Stuart D. |
| Copyright Year | 1999 |
| Description | In the wealth of EUV spectroscopic and imaging data gathered by the SOHO and TRACE missions, a prominent role is played by the helium resonance emission. For example, He I lines are among the most intense features in CDS/NIS spectra, while the EIT 304 waveband (dominated by He II emission) is routinely employed to map the structure of the solar chromosphere and transition region. However, no 'standard' model has emerged so far that is able to interpret observed He spectra/images to a satisfactory degree of self-consistency. Recent research on the problem of the formation of the solar helium spectrum tends to rule out a dominant role of coronal radiation in exciting He resonance lines. However, while evidence for this result is strong, it is based on indirect tests. Here we present a preliminary assessment of this issue based on a more direct approach, which involves a measure with CDS/GIS of the photoionizing EUV radiation. This measure can be directly compared with the observed flux in the main He I and He II resonance lines observed with CDS/NIS2. |
| File Size | 278993 |
| Page Count | 4 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19990109152 |
| Archival Resource Key | ark:/13960/t6k12177r |
| Language | English |
| Publisher Date | 1999-01-01 |
| Access Restriction | Open |
| Subject Keyword | Solar Physics Radiation Effects Solar Corona Chromosphere Soho Mission Imaging Techniques Helium Solar Spectra Photoionization H Lines Solar Transition Region Extreme Ultraviolet Radiation Transition Region and Coronal Explorer Resonance Lines Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
