On the high-energy emissions of compact objects observed with INTEGRAL SPI: Event selection impact on source spectra and scientific results for the bright sources Crab Nebula, GS2023+338 and MAXI J1820+070

Understand

The INTEGRAL SPI instrument observes the hard X-ray sky from 20 keV up to a few MeV since more than 15 years.

• In this energy domain, the main emitters are compact objects for which SPI provides spectral information of prime interest.
• Recently, two transient sources reached very unusual flux levels and have been detected up to a few hundreds of keV with a high significance level.
• A drastic reduction of the systematic errors is thus required to obtain reliable spectra.