Projects per year
In the frame of the INTEGRAL Key Programmes, more than the half of the known X-ray bursters will be observed, among which some may exhibit unusual burst events lasting between a few tens of minutes and several hours. We propose to continue our survey of such long X-ray bursts in order to investigate what conditions, depending on the composition and rate of the accretion, lead to the unstable burning of either a large pile of mixed hydrogen and helium, or the ignition of a thick pure helium layer. A link with the superbursts, that are thought to arise from deeper carbon shell flashes, will also be investigated in the eventuality of the observation of such exceptional events by INTEGRAL. Thanks to the 6 Ms total exposure time and the large field covered by the Key Programmes we may expect to observe a few of these events for which the recurrence time is estimated to be of the order of years. We want to exploit the advanced sensitivity of the INTEGRAL instruments to study the physics of such events up to high energies and compare their observational properties with theoretical predictions. We apply for Key Programme data for any bursts whose light curves show that the flux in JEM-X (3 - 20 keV) or in IBIS/ISGRI (18 – 40 keV) stays above its pre-burst level for more than 10 minutes. In order to investigate the burst properties in relation with the accretion rate history, we also ask for the subset of data concerning the persistent emission of the involved burster.
|Effective start/end date||15/08/2008 → 16/10/2010|