1. Milano, 14 February 2014 ATHENA day FABIO GASTALDELLO INAF, IASF-Milano A. DE LUCA, A. GIULIANI, N. LA PALOMBARA, S. MEREGHETTI, S. MOLENDI, A. MORETTI, M. ROSSETTI, D. SPIGA, A. TIENGO BACKGROUND CHARACTERIZATION

2. EXPERTISE  DETAILED STUDIES OF X-RAY BACKGROUND IN MANY PAST AND PRESENT SATELLITES  ANALYSIS OF GEANT 4 SIMULATIONS FOR MISSION STUDIES

3. WHY ARE WE OBSESSED WITH BKG ? De Luca & Molendi 04 Detailed knowledge of bkg is crucial to measure faint diffuse X-ray sources: outer regions of clusters and groups and the CXB

4. REPRODUCIBILITY OF BKG De Luca & Molendi 04 Stability of the spectral shape in time and across the detector is key

5. IMPORTANCE OF CORNER DATA De Luca & Molendi 04 Snapshot of the particle background at the same time of your obs

6. PUTTING ALL TOGETHER FOR CLUSTERS Leccardi & Molendi 08

7. PUTTING ALL TOGETHER FOR CLUSTERS Leccardi & Molendi 08

8. SWIFT ON A LEO Moretti+09,+11

9. EFFECT OF THE ORBIT Moretti et al in prep. Higher bkg for high orbit satellites and significant variation due to solar acitivity. In LEO even very different design (Suzaku and Swift) have similar bkg

10. SOFT PROTONS Tiengo 07

11. SOFT PROTONS Tiengo 07

12. SOFT PROTONS XMM-SOC-GEN-TN-0014 Issue 3.3

13. PROTON MAGNETIC DIVERTER Spiga+07

14. LESSONS (NOT) LEARNED Branduardi-Raymont+85

15. CONCLUSIONS  CAREFUL CHARACTERIZATION OF THE BKG FOR MANY SATELLITES CAN HELP IN IDENTIFYING PROBLEMS AND PROPOSE SOLUTIONS  BKG WILL BE CRITICAL FOR MANY OF THE SCIENCE GOALS OF ATHENA

16. SWIFT ANALYSIS Moretti+09,+11

17. SWIFT ANALYSIS Moretti+09,+11

18. SEASONAL VARIATION OF SP XMM-SOC-GEN-TN-0014 Issue 3.3

19. SEASONAL VARIATION OF SP Casale & Fauste 04

20. SEASONAL VARIATION OF SP Casale & Fauste 04