Cosmic X-ray background and Earth albedo Spectra with Swift/BAT

TL;DR

This paper presents precise measurements of the Cosmic X-ray background and Earth albedo spectra using Swift/BAT data, confirming previous results and providing insights for satellite background predictions in the 15-200 keV range.

Contribution

The study offers the first detailed Earth albedo spectrum with Swift/BAT and confirms the CXB normalization is slightly higher than previous measurements.

Findings

CXB spectrum agrees with INTEGRAL, BeppoSAX, and HEAO-1 results

BAT CXB normalization is about 8% higher than HEAO-1

Earth albedo spectrum can predict satellite photon backgrounds

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.