Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun

Details Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun

Apr 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000jkas...33...57l&link_type=abstract

Journal of the Korean Astronomical Society, vol. 33, no. 1, pp. 57-73

Astronomy and Astrophysics

Astronomy

3

Sun: Transition Region, Sun: Uv, Spectroscopy: Sumer, Nonthermal Velocity

Scientific paper

We have done a spectroscopic study of the solar transition region using high resolution UV & EUV data obtained by SUMER) on board SOHO. Optically thin and conspicuous emission lines observed at the solar limb are carefully selected to acquire average values of physical parameters for the quiet region as a function of radial distance. Our main results found from the present study can be summarized as follows. 1) Nonthermal velocities estimated from various UV lines do not decrease with height at least within one total line intensity scale height above the limb. 2) Nonthermal velocity distribution with temperature is very similar to that of the disk center, in the sense that its peak is located around 2E+5 K, but the value is systematically larger than that of the disk. 3) It is found that nonthermal velocity is inversely proportional to quadratic root of electron density up to about 10 arc seconds above the limb, i.e. ~ Ne**(-1/4), implying that the observed nonthermal broadening can be attributed to Alfven waves passing through the medium. 4) Electron density estimated from the O V 629/760 line ratio is found to range from about 1e+10 cm-3 to 2e+10 cm-3 in the transition region.

Affiliated with

Also associated with

No associations

Rating

Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nonpotential Broadening of UV Lines Observed at the Limb of the Quiet Sun will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-754771