The INTEGRAL observatory has performed the deepest survey
of the Galactic plane and the Galactic bulge ever in X-ray
astronomy. However, until recently, it was virtually impossible
to take advantage of these deep observations due to strong
systematic effects of sky reconstruction methods applied so far,
which render the identification of weak sources very difficult.
Using an improved sky reconstruction method for the IBIS/ISGRI
telescope, as described by R. Krivonos et. al., 2010 (A&A, in press),
one can effectively suppress the systematic noise and conduct the
most sensitive survey ever made of the Milky Way above 20 keV. The
faintest detectable flux, at the 5 sigma detection level, reached
0.26 mCrab in the 17-60 keV energy band. The density of sources in
the Galactic bulge region is so high, that the total number of
sources in a 20 Ms deep field is about 80 within the IBIS field of
view, which is at the limit for the coded mask telescope.
Related links:
INTEGRAL/IBIS 7-year All-sky Hard X-Ray Survey. Part I: Image Reconstruction
R. Krivonos et al.,
Accepted in A&A, 2010 arXiv:1006.2463
