Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 2003
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003a%26a...409..745m&link_type=abstract
Astronomy and Astrophysics, v.409, p.745-753 (2003)
Astronomy and Astrophysics
Astrophysics
2
Sun: Flares, Sun: X-Rays, Gamma -Rays, Plasmas, Acceleration Of Particles
Scientific paper
The 1.63 MeV gamma -ray line of 20Ne is sensitive to protons of lower energies than most other nuclear de-excitation lines. Its unexpected strength has been taken as evidence for a solar flare fast ion distribution that remains steep at low energies, and thus has a large total energy content. It has also been suggested that its strength might instead reflect the enhancement of ion lifetimes that occurs when ambient temperatures exceed 107 K. Here we revisit this idea (a) recognising that ions may be effectively trapped in high temperature regions and (b) taking account of the contribution to the line of all ions above threshold. The strength of the 1.63 MeV line relative to other de-excitation lines has been used to estimate the steepness (e.g. energy power-law index) of the ion distribution. We show that these estimates must be significantly revised if primary ions are contained in a region with temperature in the few 107 K range, lower than found elsewhere. Such a region would almost certainly be coronal, so we also briefly review other arguments for and against coronal gamma -ray sources.
MacKinnon Alexander L.
Toner M. P.
No associations
LandOfFree
Warm thick target solar gamma -ray source revisited 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 Warm thick target solar gamma -ray source revisited, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Warm thick target solar gamma -ray source revisited will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-911473