In the Forward Shock (FS) model, the GRB afterglow is produced in thecircumburst medium when the ejecta interacts with it. However, a few GRBs havean X-ray lightcurve with a very large change of decay slope, that is hard toexplain by a FS, while their optical behaviour is different and more consistentwith it. One proposed solution is that X-ray emission is produced within theejecta, and ends in a few ks. We propose to test this scenario by observing atlate epochs 2 GRBs with a large break in the X-ray lightcurve and detectedoptical afterglow with XMM-Newton. In this model, the X-ray flux at late epochsshould return to a shallower decay, similar to the optical, when the emissionfrom the FS prevails. XMM-Newton high sensitivity is required to constrain the X-ray flux at late times.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2013-05-13T03:12:55Z/2013-06-20T09:14:15Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Massimiliano De Pasquale, 2014, 'Non-forward shock components in X-ray afterglows', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-vh51ryu
