Unlocking the Future of X-Ray Polarimetry with IXPE: Lessons Learned and Next Steps

Abstract

This paper discusses issues encountered during the early development of the instrument on the Imaging X-ray Polarimetry Explorer (IXPE), a NASA ASI Small Explorer mission launched on 9 December 2021. IXPE has observed about 100 sources, yielding meaningful polarimetry for most of them. An on-board calibration system mitigated most non-ideal detector behaviors during operations. Data from the on-board polarized and unpolarized X-ray sources are routinely ingested by the flight pipeline to correct the instrument response in a manner transparent to users. Based on its scientific return and payload health, the IXPE mission has been extended through 2028. The lessons learned are informing the design of next-generation X-ray polarimetry missions, as discussed elsewhere in these conferences.

Accepted for publications in "Particles" of MDPI as reviewd proceedings of Advances in Space AstroParticle Physics (ASAPP2025) 12 16 May 2025. Sant Feliu de Guixols, Girona (ES) 16 pages; 2 tables; 10 figure