Analysis of reconnection inflow in solar flare

Noriyuki Narukage and Kazunari Shibata
(Kwasan and Hida Observatories, Kyoto University)

Solar flare is an explosion on the solar surface and releases huge energy
in a short time. It is widely believed that the energy is stored in magnetic
field and the flare is caused by magnetic reconnection. Yohkoh, a Japanese
solar X-ray satellite launched in 1991, discovered various evidence of the
magnetic reconnection. The reconnection model has been established at least
phenomenologically by Yohkoh. However, the inflow, which is predicted by the
reconnection theory, has not been discovered, and it remains mystery. In
2000,
Yokoyama et al. discovered such reconnection inflow in a solar flare
observed
with SOHO/EIT, but no other observation of reconnection inflow has been
reported until now. The generality of inflow remains doubtful.
We surveyed the reconnection inflow in the full Sun movies taken with
SOHO/EIT
and discovered 13 inflows. Moreover, we found an X-ray inflow observed with
Yohkoh/SXT. In this event, Nobeyama Radioheliograph detected the radio
source
near the SXT inflow, i.e., reconnection X-point. Using these data, we
estimated
some physical quantities of the inflows, e.g., reconnection rate,
reconnection
region, etc. This result is conclusive evidence of reconnection and the clue
to the solution of flare mechanism.