Integral Announcement of Opportunity
6 November 2000Gamma-ray astronomers and astrophysicists the world over are today being solicited for Guest Observer proposals using ESA's Integral observatory. The European Space Agency officially issued its Announcement of Opportunity (AO-1) on 1st November.
INTEGRAL is due to be launched in April 2002. Prime Contractor Alenia is currently assembling the spacecraft in Italy. The first of its four science instruments, the Optical Monitor Camera, was delivered to Turin at the end October. The gamma-ray imager (IBIS), the X-ray monitor (JEM-X) and the gamma-ray spectrometer (SPI) will be following in the coming months.
The Announcement of Opportunity concerns observations to be carried out by guest observers between July 2002 and June 2003 during the first half of the nominal two-year mission. Guest observer time in the first year will represent 65% of Integrals total observing time, the rest, Guaranteed Time, being attributed to the Integral Science Working Team including the Principal Investigators whose teams contributed the science instruments.
Response to the AO is expected to be important if one judges by the previous Call for Letters of Intent which sought to pinpoint the areas of general scientific interest. We thought we would get around 400-500 intentions for proposals, says Integral Project Scientist Chris Winkler. In fact 242 replies were received from 20 different countries, formulating a total of about 700 proposals, so we expect that the available observing time will be heavily oversubscribed.
To avoid duplication, notification of the Announcement of Opportunity was accompanied by documents detailing the Guaranteed Time Core Programme. This will include frequent scans to map the Galactic plane and detect transient gamma-ray sources; a deep survey of the central region of the Galaxy to perform deep imaging and spectroscopic studies and to identify nucleosynthesis radioisotopes; and pointed observations of selected sources, including the Vela region which includes a wide variety of extreme energy sources in the Integral spectral domain.
Chris Winkler is confident that as many guest observer proposals as possible will be accepted. We can amalgamate observations, by including two or three selected targets which are close enough in the sky in one single observation. Remember the wide field of view of the SPI spectrograph can reach 16x16 degrees square, and the IBIS imager 9x9 square degrees.
All the proposals to use the gamma-ray observatory have to be submitted by 16 February 2001. They will then be subject to an independent peer review by the Integral Time Allocation Committee (TAC). The final approved observation programme will be available in June 2001.
In conjunction with the AO-1 release, the missions Science Operations Centre (ISOC), located at the Agencys ESTEC facilities in the Netherlands, has published its first Newsletter. It has also inaugurated a public/visitors area. A 1:10 scale model of Integral has been installed, with accompanying posters. In the future, screens will display an animation of the spacecraft in orbit, sky maps with actual Integral pointings and science results when the mission is underway.