INTEGRAL insights to the inner parts of the Galaxy
INTEGRAL has devoted a large fraction of the available
observation time to the Galactic center region resulting in
some new insights on the inner Galaxy arms (Norma, Scutum, Sagittarius).
In a paper submitted to Astronomy and Astrophysics
Lutovinov et al. discuss the density of High Mass X-ray Binaries
(HMXB) towards the Galactic centre. Since INTEGRAL observes in
the hard X-ray band it has an increased sensitivity to absorbed
sources, resulting in a larger sample of HMXB's.
In the figure the density of HMXB's is represented by a grey scale and
the spiral arms are indicated. The star denotes the position of the
Galactic centre, the circle with the dot the position of the sun. The
highest density ("dark grey") is found in the general direction of
the Norma arm.
However the maxima in the HMXB density do not coincide exactly with
the current position of the spiral arms. Lutovinov et al. argue that the
highest density of HMXB is found where star formation was taking place
about 10 million years ago.
