On the morphology of the electron-positron annihilation emission as seen by SPI/INTEGRAL

Understand

The 511 keV positron annihilation emission remains a mysterious component of the high energy emission of our Galaxy.

• Its study was one of the key scientific objective of the SPI spectrometer on-board the INTEGRAL satellite.
• In fact, a lot of observing time has been dedicated to the Galactic disk with a particular emphasis on the central region.
• A crucial issue in such an analysis concerns the reduction technique used to treat this huge quantity of data, and more particularly the background modeling.