Proposal Details - 0920005
Keeping watch over our Galaxy - the return of the GPS (Bazzano)

Proposal Abstract

For the first 5 years of INTEGRALs operational life, the scientific Core Programme included a key component that was regular scans of the Galactic Plane. These led to a wealth of discoveries of new sources and source types, a large fraction of which were highly transient. These discoveries can certainly be considered one of the strongest results from, and legacies of, INTEGRAL. Since AO-5, these regular scans have been discontinued, and this has resulted in a significant drop in the discovery rate of new systems in and around the plane of our Galaxy. It is proposed to reinstate the Galactic Plane Scans as a Key Programme throughout AO8 and AO9, to allow the regular monitoring of known systems, and dramatically enhance the chances of discovering new systems. Such a programme will be of high value to a very large fraction of the high energy astronomy community, stimulating science immediately, and furthermore contributing greatly to the INTEGRAL legacy.To this aim, a total of 2 Msec /year are necessary to cover the plane with regular scans every orbit, excluding the central zone to be covered by the Galactic Bulge monitoring programme (see proposal 0920001). In order to maximise the engagement of the scientific community, the observations should be made public immediately. The proposers team will make the IBIS and JEM-X light curves in two energy bands per science window and per observation, as well as the mosaic images publicly available through the web as soon as possible after the observations have been performed. Any interesting source behaviour that emerges from these observations will be announced promptly, so that rapid follow-up by the community is possible.

Observation Strategy (Recommended by TAC)

Total of 2 Ms along the Galactic plane, split into various scans. Basically, the scans will be performed by executing a continuous slew and stare manoeuvre of the spacecraft along the visible (accessible) part(s) of the Galactic plane with an extension in latitude up to ±10 degrees. The angular distance between two staring points along the scan path is 7 degrees, the extremes in latitude of the pointings are at b = ±6.45 degrees. The scans will be performed in a saw-tooth pattern with inclination of 17.8 degrees with respect to the Galactic plane, each subsequent scan being shifted by 27.5 degrees in longitude. The accessible part of the Galactic plane depends on viewing constraints, including the solar aspect angle, and on the season of the year. Figure 7 of the AO-3 INTEGRAL Guaranteed Time document shows the Galactic plane visibility for GPS scans. A schematic view of two consecutive scans in shown in Figure 8 of the AO-3 INTEGRAL Guaranteed Time document

Proposal grade: A

Data Rights (Recommended by TAC)

All data are public