FXT Data Center

FXT DAS

The Follow-up X-ray Telescope Data Analysis Software (FXTDAS) is to achieve the EP-FXT data analysis processing and extract scientific products, e.g. energy spectra, images, light curves, ancillary response files (ARF), redistribution matrix files (RMF) and background files.

FXT has three scientific observation modes: the full frame mode (FF), the partial window mode (PW) and the timing mode (TM), and FXTDAS is designed to allow the general users to analyse FXT data observed in these modes.

The software is written in ftools style and are fully compatible with the HEASoft software.

FXT DAS - Latest Version

Version 1.30 Updates:

Data Analysis Software:

1. Added a PSF map estimation module (fxtpsfmap) for generating a PSF map at a specified energy and enclosed energy fraction (EEF).

2. Updated the ARF generation module (fxtarfgen) on PSF correction (psfcor=1) for near on-axis point sources (support for circle, ellipse, and rectangle regions).

3. Updated the PI calibration module (fxtpical) on time-dependent drift of gain.

4. Optimized the shared telescope-definition handling in fxteefgen, fxtpsfgen, and fxtpsfmap.

Calibration Database:

1. Extended the low-energy coverage of both the E-C calibration and ARFs down to 0.3 keV.

2. Updated the RMFs, including the platform component and the energy resolution.

3. Updated the vignetting calibration.

4. Updated the time-dependent variation of the E-C relationship.

5. Updated the on-axis PSF calibration.

Bug Fixes:

1. Found and corrected an extra +1 in fxtexpogen.

2. Fixed the EEF file path setting issue in fxteefgen.

We recommend users to use fxtchain (refer to the USER GUIDE 1.30) to complete routine FXT data analysis, and to use the updated CalDB tools for calibration, response, and PSF/EEF related analysis when needed.

You can download the source code of FXTDAS. In addition, the latest CALDB package and docker image are also provided. If you encounter any installation problem, it is recommended to use the docker version, or please report them on the helpdesk.

*Source code for linux:

EP-FXT software v1.30 source code for linux or IHEPDocs: EP-FXT software v1.30 source code for linux

*Docker image:

When loading a Docker image, use docker load < x.tar.gz for compressed files ending in .tar.gz, and use docker load -i x.tar for uncompressed files ending in .tar.

IHEPDocs: EP-FXT software v1.30 docker image

FXT DAS - Historical Version

EP-FXT software v1.20

2026/03/31

EP-FXT software v1.10

2025/05/29

EP-FXT software v1.05

2024/09/27

FXT CALDB

The Einstein Probe Follow-up X-ray Telescope (EP-FXT) Calibration Database (CALDB) is an essential resource for researchers working with EP-FXT data. The CALDB contains a comprehensive collection of calibration files necessary for accurate data reduction and analysis. These files provide detailed information about the properties and performance of the EP-FXT detectors, mirrors, and other instrument components. The CALDB is organized into a well-defined directory structure, making it easy for users to locate and access the calibration files required for their specific analysis tasks.

Some of the key calibration files included in the EP-FXT CALDB are:

1）Ancillary Response Files (ARF): These files contain information about the effective area of the detectors and mirrors as a function of energy.

2）Response Matrix Files (RMF): These files characterize the energy response of the EP-FXT detectors, accounting for energy dispersion and detector resolution.

3）Point Spread Function (PSF) files: These files describe the spatial distribution of X-ray photons as they are focused by the EP-FXT mirrors.

4）Energy Encircled Fraction (EEF) files: These files provide information on the fraction of energy contained within a given radius for a point source.

5）Telescope Definition (TELDEF) files: These files describe the geometry and alignment of the EP-FXT detectors and mirrors.

6）Vignetting files: These files contain information on the reduction of the telescope's effective area due to off-axis angles.

7）Filter Transmission (FTRANS) files: These files describe the transmission properties of the filters used in EP-FXT.

8）Quantum Efficiency (QE) files: These files provide information on the detectors' sensitivity to incoming photons as a function of energy.

9）Gain and Charge Transfer Inefficiency (GAIN) files: These files contain information about the gain calibration and charge transfer inefficiency of the EP-FXT detectors.

10）Mirror effective area (EFF) files: These files provide data on the reflectivity and efficiency of the EP-FXT mirrors as a function of energy.

11）Background files: These files contain information on the instrumental and astrophysical background components relevant to the EP-FXT observations.

The EP-FXT CALDB plays a crucial role in ensuring that researchers can obtain the most accurate and reliable results from their analysis of EP-FXT data. By providing up-to-date calibration information, the CALDB enables scientists to fully exploit the exceptional capabilities of the Einstein Probe Follow-up X-ray Telescope and contribute to the advancement of our knowledge of the high-energy universe.

FXT CALDB - Latest Version

Version Information

Release: FXT CALDB v1.30

Scope: Energy scale calibration, ARFs down to 0.3 keV, RMF energy resolution and platform component,
vignetting, time-dependent E-C variation, and on-axis PSF

This release updates the calibration database to improve spectral accuracy and consistency

across the low-energy band and the instrument response.

It is recommended for all users performing spectral, response-sensitive, or PSF-related studies.

What’s New:

1. Updated the E-C relationship and extended the

low-energy coverage of both the E-C calibration and ARFs down to 0.3 keV.

2. Updated the response matrix, including the platform component and the

energy resolution, to better reproduce the instrument response.

3. Updated the vignetting calibration.

4. Updated the time-dependent variation of the E-C relationship.

5. Updated the on-axis PSF calibration.

No changes are required to analysis workflows beyond updating to this CALDB.