Extreme-ultraviolet spectral line widths in quiet-Sun coronal plasmas at distances of 1.03 ≤ R⊙ ≤ 1.45 along the solar equatorial plane

We measure the full width at half-maximum intensity (FWHM) of extreme-ultarviolet (EUV) spectral line profiles as a function of height in the Sun's equatorial west limb streamer region using EUV spectra recorded by the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) spectrometer on the Solar and Heliospheric Observatory (SOHO) spacecraft. The spectra were recorded on 1996 November 21 and 22, during a special roll maneuver in which the SUMER slit was oriented in the east-west direction. Because the SUMER spectrometer is stigmatic along the slit length, the spectra are spatially resolved in the east-west direction. The spectra we discuss cover an effective distance range outside the west limb from 1.03 to 1.45 R.; the maximum spatial resolution is 1 . We select a group of emission lines for analysis that under the usual ionization equilibrium assumption have maximum fractional abundances at temperatures ranging from 3 x 10(5) up to 2 x 10(6) K. We determine nonthermal motions as a function of position in the streamer region from the FWHMs under the assumption that the ion temperature equals the electron temperature of the streamer plasma. The electron temperature was derived previously by Feldman and coworkers.