Detection of Multiple Hard X-ray Flares from Sco X-1 with OSSE
M.S. Strickman
D. Barret
Abstract
Although recent results have firmly established the presence of hard X-ray
emission from low
luminosity low mass X-ray binaries (e.g. X-ray bursters), high luminosity
LMXB are generally associated
with relatively soft spectra. In 5 weeks of observation of the high
luminosity
LMXB Sco X-1, the OSSE instrument on CGRO has observed three episodes of
hard X-ray flaring,
during which the source spectrum displays a definite hard X-ray tail
extending to as much as 200 keV.
The tail, which diverges from the low-energy spectrum above 80 keV, is
consistent with
power-law shapes with photon index between 2.5 and 3.
The flaring episodes last a few days and may have a relatively high duty
cycle. We will present
the observational evidence for these flares and discuss some of the
implications they have for
models of luminous LMXB emission.
File translated from TEX by TTH, version 2.32.
On 16 Jul 1999, 09:19.