About IXPEIXPE's two-year baseline IXPE mission will measure the x-ray polarization of cosmic sources, using three identical telescopes, each comprising an x-ray mirror assembly and a polarization-sensitive detector. The mission, a collaboration between NASA and the Italian Space Agency (ASI), is led by the Principal Investigator (PI), Dr. Martin C. Weisskopf at NASA's Marshall Space Flight Center (MSFC). MSFC manages the project and is responsible for the x-ray optics and the Science Operations Center (SOC). Italy's National Institute for Astrophysics (INAF) and National Institute for Nuclear Physics (INFN) are responsible for the x-ray instrument. Ball Aerospace is the primary industry partner, responsible for the spacecraft, integration, and testing, as well as managing the Mission Operations Center (MOC) at the University of Colorado's Laboratory for Atmospheric and Space Physics (LASP). In addition to funding the Instrument at INAF, INFN, and industrial partner OHB-Italia, ASI provides IXPE use of its Malindi ground station and software support by its Space Science Data Center (SSDC). The SOC will archive IXPE science data products at the High-Energy Astrophysics Science Archive Research Center (HEASARC) at NASA's Goddard Space Flight Center (GSFC), for release to the international scientific community. The IXPE Science Team comprises investigators from MSFC, INAF, INFN, and three universities --- Roma Tre University, Stanford University, and the Massachusetts Institute of Technology --- plus over 80 collaborators from more than a dozen countries. During the first two years of the mission, the IXPE Science Team develops and executes the IXPE observing program. If the mission extends beyond two years, the HEASARC will administer a General Observer (GO) program for IXPE. IXPE scienceIXPE accomplishes new science with new capabilities
IXPE observatory
IXPE mirrors
The polarization sensitive detectors
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Latest NewsThe due date for IXPE Cycle 4 proposal submission is Sept 17, 2026. Proposals should be submitted via the HEASARC's ARK Remote Proposal System (RPS). For more information about this cycle, please visit the IXPE Cycle 4 Guide for Proposals Page. IXPE Cycle 4 proposers should note that the required one paragraph work plan has been moved to the Non-anonymized Expertise and Resources (E&R) document and should be non-anonymized. Consequently, the page limit for the E&R document has now been increased to 2 pages. For more information, please visit the Cycle 4 proposal guide. For any questions about proposal submission and guidelines, please contact the IXPE help desk. The IXPE Caldb has been updated for the GPD (version 20260610) and XRT (version 20260609). Downloads are available from the IXPE Calibration page. Users can also access the HEASARC IXPE caldb via remote access. Delivery of data from IXPE's Detector Unit 2 (DU2) has resumed. The IXPE team performed an extensive recalibration campaign including 2.7 Ms of exposure on the bright X-ray binary Cyg X-2 in December 2025 and January 2026. The recalibration has successfully restored the polarization and spectral response of DU2. All data since the anomaly in April 2025 have been reprocessed and re-delivered with DU2. Data delivery for new observations now includes DU2. Users are encouraged to compare the results obtained with the different DUs and report any significant discrepancies via the IXPE Help Desk. For more information on the anomaly, please see this presentation by the IXPE SOC. The IXPE Caldb has been updated for the GPD (version 20260424) and XRT (version 20260331). Downloads are available from the IXPE Calibration page. Users can also access the HEASARC IXPE caldb via remote access. |



