Data reduction and processing for the Follow-up X-ray Telescope onboard Einstein Probe

Purpose The Follow-up X-ray Telescope (FXT) is a principal scientific payload onboard the Einstein Probe (EP). It is designed to be capable of localizing X-ray sources, measuring the energy spectra in X-ray band of 0.3–10 keV, and in some cases, performing observations with high time resolution. The FXT consists of two X-ray mirror modules (FXTA and FXTB), each containing 54 nested Wolter-I paraboloid–hyperboloid mirror shells. Each module is equipped with a PN-CCD as the focal plane detector. In order to complement the capabilities of the FXT, the PN-CCD offers three readout modes, full field of view imaging with low time resolution mode (FF mode), partial window imaging with moderate time resolution mode (PW mode) and high time resolution mode (TM mode). These different modes require tools and algorithms for data reduction and analysis.
Methods A software package is utilized to achieve the FXT data analysis processing and extract scientific products. In the data reduction, time correction, computation of the PI values, elimination of the events caused by particles, identification of anomalous pixels and columns, and event reconstruction will be provided. Generic tools from HEASOFT, such as Xselect and Xspec, can also be used to manipulate the data files of the FXT.
Results The FXT data are distributed in FITS format files. Its software package was created by taking the FXT-specific tools and the generic tools, and re-packaging them as stand-alone application. And the FXT-specific tools are written in ftools style, and the run styles are fully compatible with the HEASOFT software.
Conclusion This package can achieve the FXT data analysis processing for all three science modes and effectively meets the data analysis requirements of the FXT.