Flaring Time Interval Distribution and Spatial Correlation of Major X-ray Flares
Yong-Jae Moon Submitted: 2002-04-05 17:52
A statistical study is performed on X-ray flares stronger than C1 class that erupted
during the solar maximum between 1989 and 1991. We have investigated the flaring
time interval distribution (waiting-time distribution) and the spatial correlation of
successive flare pairs. The observed waiting-time distribution for the whole data is
found to be well represented by a nonstationary Poisson probability function with time
varying mean flaring rates.
The period most suitable for a constant mean flaring rate is determined
to be 2-3 days by a Kolmogorov-Smirnov test.
We have also found that the waiting-time distribution for flares in
individual active regions follows a stationary Poisson probability function
mexp(-mt) with a corresponding mean flaring
Therefore, the flaring probability within a given time is given by 1-exp(-mt), when
the mean flaring rate m is properly estimated.
It is also found that there is no systematic relationships between peak fluxes of
flares and their waiting-time distributions.
The above findings support the idea that the
solar corona is in a self-organized critical state.
A comparison of the angular distances of successively observed flare pairs with those of
hypothetical flare pairs generated by random distribution shows a positive angular
correlation within about 10 degrees (sim 180 arcsec in the observing field)
of angular separation, which suggests
that homologous flares occurring in the same active region should outnumber
Authors: Y.-J. Moon, G. S. Choe, H. S. Yun, Y. D. Park
Publication Status: JGR-space physics, 2001, 106(A12), 29951-29961
Last Modified: 2002-04-05 17:52