CAPIGX focuses on monitoring and following-up gamma-ray and X-ray transient events-the highest-energy forms of light in the Universe. These photons are emitted during cataclysmic events like black hole mergers and last only for a few seconds. Our mission aims to fill the upcoming observational gap in the 1 kev - 1 MeV range and push the limits of angular resolution with intensity interferometry. Our mission, set to launch between 2032–2035, will come in the era of multi-messenger astrophysics with many key X-ray and gamma-ray space telescopes (NewAthena, THESEUS) and gravitational wave observatories (Einstein Telescope, Cosmic Explorer, LISA) going online.
Intensity Interferometry
The technique of intensity interferometry has been previously used by the interplanetary network (IPN) to efficiently localize transients. Our mission proposes using a small constellation of CubeSats to help constrain the coordinates for source localization. With different CubeSats located at a baseline distance, different signal times of arrival (ToA) are used to compute and reduce the uncertainty of the source location. Following the steps of the HERMES mission, we aim to extend this to the 2030s and enhance the angular resolution capabilities for multi-messenger events.
Instruments
To cover the observational gap in the keV to MeV range, we need to combine X-ray and gamma-ray instruments with segmentation at 150 keV.
- 1-150 keV (X-ray): Cadmium Zinc Telluride (CZT) detectors
- 0.15-1 MeV (hard X-ray/gamma-ray): Cesium Iodide (CsL(TI)) with Silicon Photomultipliers (SiPMs)
