Emission-line spectra of two active regions on the solar limb: 1175 - 1940 Å.
Abstract
Skylab emission-line spectra (1175 to 1940 A) of two active regions on the solar limb are examined. Electron densities for the active regions are derived using the intensity ratios of selected intersystem and allowed lines. The intensity ratios in the active regions are compared with those observed previously in quiet-sun and coronal-hole regions. The behavior of coronal forbidden lines relative to transition-zone lines is discussed along with the solar continuum intensities near and above the limb. These continuum intensities are then compared with those at similar slit positions for the quiet sun and the previously studied coronal hole. The active-region data are found to be consistent with either (1) multithermal loops with the high-temperature plasma occupying the tops of the loops or (2) nearly isothermal loops with the hotter loops extending to higher altitudes.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- August 1978
- DOI:
- 10.1086/190537
- Bibcode:
- 1978ApJS...37..443F
- Keywords:
-
- Emission Spectra;
- Line Spectra;
- Solar Corona;
- Solar Spectra;
- Spectrum Analysis;
- Ultraviolet Spectra;
- Forbidden Bands;
- Skylab Program;
- Solar Activity;
- Solar Physics;
- Solar Active Regions:UV Spectra