XMM-Newton Users Handbook


next up previous contents
Next: 3.3.7.1 EPIC external `flaring' background Up: 3.3 EUROPEAN PHOTON IMAGING CAMERA (EPIC) Previous: 3.3.6 EPIC filters and effective area


3.3.7 EPIC background

The EPIC background can be divided into two parts: a cosmic X-ray background (CXB), and an instrumental background. The latter component may be further divided into a detector noise component, which becomes important at low energies (i.e. below 300 eV) and a second component which is due to the interaction of particles with the structure surrounding the detectors and the detectors themselves. This component is characterised by a flat spectrum and is particularly important at high energies (i.e. above a few keV).

The particle induced background can be divided into 2 components: an external `flaring' component, characterised by strong and rapid variability, which is often totally absent and a second more stable internal component. The flaring component is currently attributed to soft protons ($E_p$ smaller than a few 100 keV), which are presumably funnelled towards the detectors by the X-ray mirrors. The stable component is due to the interaction of high-energy particles ($E$ larger than some 100 MeV) with the structure surrounding the detectors and possibly the detectors themselves.

A table summarising the temporal, spectral and spatial properties of the EPIC background components is available at http://www.star.le.ac.uk/$\sim $amr30/BG/BGTable.html.

The SOC has performed an analysis of the behaviour of the XMM-Newton background from the beginning of the mission (available as XMM-SOC-GEN-TN-0014). Main conclusions are:



Subsections
next up previous contents
Next: 3.3.7.1 EPIC external `flaring' background Up: 3.3 EUROPEAN PHOTON IMAGING CAMERA (EPIC) Previous: 3.3.6 EPIC filters and effective area
European Space Agency - XMM-Newton Science Operations Centre