XPoSat is India's first X-ray spectro-polarimetry mission, consisting of two co-aligned instruments, a polarimeter (POLIX) and a spectrometer (XSPECT), to study the X-ray emission from celestial sources. Since polarimetry is a photon-hungry technique, the mission is designed to observe sources for long integration times (~ few days to weeks). This provides an unique opportunity, enabling XSPECT to carry out long-term monitoring of sources, and study their spectro-temporal evolution. To ensure that the instrument is able to fulfill its scientific objectives, it was extensively calibrated on-ground. Post launch, these calibrations were validated using on-board observations. Additionally, some aspects of the instrument such as alignment and effective area were also derived and fine-tuned from in-flight data. In this paper, we describe the calibration of XSPECT instrument in detail, including some initial results derived from its data to establish its capabilities.
@article{arxiv.2506.09918,
title = {XSPECT on-board XPoSat: Calibration and First Results},
author = {Rwitika Chatterjee and Koushal Vadodariya and Radhakrishna Vatedka and Vivek Kumar Agrawal and Anurag Tyagi and Kiran M Jayasurya and Shyam Prakash V. P. and Ramadevi M C and Vaishali Sharan},
journal= {arXiv preprint arXiv:2506.09918},
year = {2026}
}
Comments
29 pages, 19 figures, 3 tables. Published in JATIS