XL-CALIBUR is a NASA scientific balloon project. Its main objective is to measure polarization of hard X-ray wavelengths for specified sources
Goals
- To constrain the properties of the X-ray intensive accretion disk coronas emitted by growing black holes and neutron stars and better define them
- To test strong-field quantum electrodynamics by using polarization measurements from neutron stars
- To find out the origin of X-ray from rotation-powered (Crab pulsar) and accretion-powered neutron stars (GX 301-2)
System
- Gondola and pointing control system using an extreme altitude balloon that can lift XL-CALIBUR to the stratosphere at an altitude of ~40 km - NASA Wallops Space Flight Center
- Fully active shield - KTH, Sweden
- Mirror from flight spare from the Hitomi Mission
- Two flights are planned
- Jukkasjärvi, Sweden - Observe sources in the Northern hemisphere for 6-7 days
- McMurdo Research Station, Antarctica - Observe sources in the Southern hemisphere for 8-55 days
XL-CALIBUR’s data will be coordinated with the following other projects:
- Imaging X-ray Polarimetry Experiment (IXPE) by NASA
- Neutron Star Interior Composition Explorer Mission (NICER)
- Nuclear Spectroscopic Telescope Array (NuSTAR)