On December 18 and 19, 2023, ISRO organized the second user meet for the upcoming XPoSat mission in ISRO Headquarters, Bengaluru. The first user meet for XPoSat was organised by ISRO on May 25, 2023. The second user meet was conducted to appraise the users about the readiness of the XPoSat mission, the status and the laboratory performance of the scientific payloads, the software chain, ground segment, proposal processing system, unique science cases relevant to the mission, and many other facets of the mission that are of interest to the user community. The user meet was conducted in hybrid mode, where a gamut of astronomers from various academia and institutes participated in person, while many users participated online.

The XPoSat (X-ray Polarimeter Satellite) is India’s first dedicated X-Ray polarimetry mission to study in depth, the physics of the cosmic X-Ray sources from the Low Earth Orbit (LEO) of ~650 km altitude, and a low inclination of 6 degree. The primary payload POLIX (Polarimeter Instrument in X-rays) will measure the polarimetry parameters (degree and angle of polarization) in medium X-ray energy of 8-30 keV from astronomical X-Ray sources. The XSPECT (X-ray Spectroscopy and Timing) payload will provide spectroscopic information in the energy range of 0.8-15 keV. The POLIX payload is developed by Raman Research Institute, Bengaluru in close coordination with ISRO.

The User Meet has participation from about 23 Institute/Universities all across the country. A total of about 180 participants attended the meeting in which 90 attended in-person and other participated through online platform. During these two days of event, there were six scientific/technical sessions on the Mission aspects, details on the laboratory performance of the scientific payloads, software tools (proposal processing, XPoviewer, etc.), science problems of priority, joint observation between XPoSat and IXPE (NASA), as well as an intense open discussion on future of X-Ray polarimetry missions with pan-India participation.

Following the meeting, the Astronomy community of India expressed satisfaction for the readiness of the XPoSat mission. They also discussed, in depth, about the specific scientific problems to address with the XPoSat observations. The discussions on the proposal processing system yielded clarity on the utilization of the XPoSat and readiness for scientific data analysis. The meeting was also attended by the senior students in Astronomy, who expressed unanimously that X-Ray polarimetry will dominate the realm of X-Ray polarimetry in near future, and this mission has indeed been a timely action in the right direction. The open discussion on future X-Ray polarimetry missions from India elaborated on these aspects and gathered the views of the X-Ray astronomers who participated in the meeting, who unanimously expressed the need for a series of X-Ray polarization missions in near future, in order to address some of the open problems in X-Ray Astronomy.