This movie is composed of the sequence of individual observations performed about every three days from February 2005 to April 2006, during the Galactic bulge monitoring by the IBIS/ISGRI instrument on board Integral.

According to the Integral observations in April 2006, the high-energy rays from a handful of sources closest to the galactic centre, most of which are X-ray binaries, all faded temporarily.

The fortuitous dimming allows astronomers to set new limits on how faint these X-ray binaries can become. It also allows a number of new investigations to be undertaken with the data.

The movie covers a sky area of 5.3x4.1 degrees, centred on the Galactic Centre. In this version of the movie a few frames have been removed to facilitate the download. The complete (high-resolution) version can be obtained by clicking here .

Credits: ESA/ISDC

Surprisingly, the sources were ‘off’ around the time of the observation (including the normally bright well-known black-hole candidate and micro-quasar 1E 1740.7-2942), displaying an unusually ‘quiet’ galactic centre. This is a very different view from those obtained on the long-term average.

The sources and the positions marked in white are almost permanently visible, while those marked in red are known ‘transient’ sources, that is sources more often ‘off’ than ‘on’.

The source called 1E 1740.7-2942 is normally the brightest source in the Galactic Centre region. It is a well-known black-hole candidate, as well as a micro-quasar source. The massive black hole at the very centre of our Galaxy, Sagittarius A* (or Sgr A*), is very close to source marked as ‘1’, corresponding to IGR J17456-2901.

The image covers a sky area of 4.3x2 degrees, and it is centred on (0, -0.5) degrees in Galactic coordinates.

Credits: ESA/ISDC

Differently from the previous image, this view was built with all exposures taken during the 1.5 years of Integral’s Galactic bulge monitoring, thus providing an ‘average’ view of the area.

By comparing this view with the previous one, it is possible to observe the highly variable nature of the sources.

In particular, the sources and the positions marked in white are almost permanently visible, while those marked in red are known ‘transient’ sources, that is sources more often ‘off’ than ‘on’.

The source called 1E 1740.7-2942 is normally the brightest source in the Galactic Centre region. It is a well-known black-hole candidate, as well as a micro-quasar source. The massive black hole at the very centre of our Galaxy, Sagittarius A* (or Sgr A*), is very close to source marked as ‘1’, corresponding to IGR J17456-2901.

The image covers a sky area of 4.3x2 degrees, and it is centred on (0, -0.5) degrees in Galactic coordinates.

Credits: ESA/ISDC