Cosmic X-Ray Background and Earth Albedo Spectra with Swift BAT
Greiner, J.; Strong, A. W.; Ajello, M.; Gehrels, N.; Hasinger, G.; Diehl, R.; Kanbach, G.; Sato, G.; Willis, D. R.; Markwardt, C. B.; Tueller, J.
Germany, United States
Abstract
We use Swift BAT Earth occultation data at different geomagnetic latitudes to derive a sensitive measurement of the cosmic X-ray background (CXB) and of the Earth albedo emission in the 15-200 keV band. We compare our CXB spectrum with recent (INTEGRAL, BeppoSAX) and past results (HEAO-1) and find good agreement. Using an independent measurement of the CXB spectrum we are able to confirm our results. This study shows that the BAT CXB spectrum has a normalization ~8% +/- 3% larger than the HEAO-1 measurement. The BAT accurate Earth albedo spectrum can be used to predict the level of photon background for satellites in low Earth and mid inclination orbits.