EUV SPECTRAL-LINES FROM SOLAR-WIND SOURCE REGIONS - THE RESONANCE DOUBLETS OF NV, MGX AND SIXII, AND THE FEXII LAMBDA-1242 FORBIDDEN LINE

We present numerical simulations of intensities and profiles of the N V lambda 1239 and lambda 1243, Mg X lambda 610 and lambda 625, Si XII lambda 499 and lambda 521, and Fe XII lambda 1242 lines expected from an equatorial and polar coronal hole at solar minimum, when observed o n the plane of the sky in the 1.2 R(.) - 8 R(.) range of heliocentric distance. The radial variations of coronal temperatures, densities and outflow speeds inside these structures are those determined by Withbr oe (1988) through a one-fluid steady-state radiative energy balance mo del. We discuss how the spectral features depend on the physical param eters of the examined structures, in order to evaluate to which extent they can put constraints on empirical models of the extended corona. We also investigate the effects of the deviations from ionization equi librium occurring in the plasma outflowing from the considered coronal structures on the intensity and profile of the spectral lines examine d. Such effects become significant at heliocentric distances higher th an 3 R(.). These results may contribute to prepare and interpret UVCS/ SOHO future observations.