Speaker
Description
The soft X-ray photometric records from the GOES/XRS instruments
now approach a half century of coverage, and constitute the most
complete space-based proxy for solar flare X-ray luminosities and
energies. Observations continue with the GOES-16 and -17 and
forthcoming satellites, which use a slightly different detector
technology. Some of the most powerful earlier events saturated the
telemetry range of their ionization-chamber detectors, making it
difficult to study the event distribution function at its most
interesting top end. Over the interval 1976--2015 a total of 11
events saturated the key 1--8 Achannel, many of which were from
NOAA region 6659 in 1991. We have devised an algorithm for best
estimates of the peak fluxes for these saturated events. Based on
this new input, and our understanding of the calibration issues for
GOES-15 and earlier, we discuss the event distribution function
(e.g. Aschwanden & Freeland, 2012) looking for evidence of a
downward break in the event distribution in the vicinity of magnitude
X10. Note that the absolute calibration of this level is under
investigation at present, but this does not concern the relative
magnitude distribution. Any departure from the power law will
crucially affect our understanding of ``superflare'' occurrence on
the Sun.
