The chromosphere-corona transition zone above an active region |
| |
Authors: | O. Kjeldseth Moe Ø. Andreassen P. Maltby J.-D.F. Bartoe G.E. Brueckner K.R. Nicolas |
| |
Affiliation: | 1. Institute of Theoretical Astrophysics, University of Oslo, Norway;7. E.O. Hulburt Center for Space Research, US Naval Research Laboratory, Washington, DC, USA |
| |
Abstract: | Intensities and profiles of ion emission lines between 1170 A and 1700 A from an active region on the Sun are measured from spectra obtained with the Naval Research Laboratory's High Resolution Telescope and Spectrograph - HRTS. The measurements provide simultaneous determination of line intensities, wavelength shifts and Doppler widths at 50 separate positions in the active region, with spatial resolution of 1 arc second and spectral resolution 0.07 A. Fine structure variation of intensities and gas flow velocities in the temperature range 20,000–200,000 K are determined. The density sensitive line pair I(1486 N IV)/I(1548 C IV) has been used to measure electron pressures. Derived emission measures imply filling factors of 0.05–0.1 to balance the divergence of conductive flux width radiative losses above 60,000 K. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|