2018/07/04 by Edoardo Cucchetti, Cucchetti, Edoardo, F. Pajot +22
Engineering · Physics and Astronomy · #Adaptive optics and wavefront sensing #Calibration and Measurement Techniques #FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM) #Superconducting and THz Device Technology
paper · pdf · doi:10.48550/arxiv.1807.01582
openalex publication_date 2018/07/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
With its array of 3840 Transition Edge Sensors (TESs) operated at 90 mK, the\nX-Ray Integral Field Unit (X-IFU) on board the ESA L2 mission Athena will\nprovide spatially resolved high-resolution spectroscopy (2.5 eV FWHM up to 7\nkeV) over the 0.2 to 12 keV bandpass. The in-flight performance of the X-IFU\nwill be strongly affected by the calibration of the instrument. Uncertainties\nin the knowledge of the overall system, from the filter transmission to the\nenergy scale, may introduce systematic errors in the data, which could\npotentially compromise science objectives - notably those involving line\ncharacterisation e.g. turbulence velocity measurements - if not properly\naccounted for. Defining and validating calibration requirements is therefore of\nparamount importance. In this paper, we put forward a simulation tool based on\nthe most up-to-date configurations of the various subsystems (e.g. filters,\ndetector absorbers) which allows us to estimate systematic errors related to\nuncertainties in the instrumental response. Notably, the effect of\nuncertainties in the energy resolution and of the instrumental quantum\nefficiency on X-IFU observations is assessed, by taking as a test case the\nmeasurements of the iron K complex in the hot gas surrounding clusters of\ngalaxies. In-flight and ground calibration of the energy resolution and the\nquantum efficiency is also addressed. We demonstrate that provided an accurate\ncalibration of the instrument, such effects should be low in both cases with\nrespect to statistics during observations.\n