Pipeline Modules and Usage

This section provides complete usage of each module of the pipeline listing all the available parameters. Hidden optional parameters are listed in square brackets.

1. cztpipeline

Purpose

This script is used to run all modules of CZTI pipeline together for the requires stages of the pipeline.

Parameters

2. cztscience2event

Purpose

This module reads the level 1 science data file and decodes the data packets into events and generate the raw event file. Timestamps for events are also assigned. Relevant housekeeping information present in headers and detector temperature information present in modeSS data are also decoded and written to output files.

Parameters

3. cztbunchclean

Purpose

This module identifies multi-hit events bunched in time due to charged particles and removes those events. It also keeps track of the dead time caused by this and records this in an output live time file generated along with the output event file.

Parameters

4. cztpha2energy

Purpose

This module uses temperature dependent pixel wise gain values from ground calibration to estimate the nominal energy of the incident photon from the recorded PHA, and expresses it on a Pulse Invariant and Pixel Invariant scale, called a PI channel value. It adds two columns to the event file named Energy and PI.

Parameters

5. cztgtigen

Purpose

This module creates the good time interval (GTI) file for each quadrant of CZTI based on thresholds on various parameters given as input, as well as the default GTI present in the event file that accounts for data gaps etc. It also has provision to accept user defined GTIs for specific analysis cases.

Parameters

6. cztgaas

Purpose

This module computes the time dependent pointing direction of CZTI axes as well as the average value required for assigning coordinates for images.

Parameters

7. cztdatasel

Purpose

This pipeline module filters the events in the input event file based on the GTI file provived and generates an output event file with the selected events.

Parameters

8. cztpixclean

Purpose

This pipeline module filters the event file for noisy pixels and detectors. It identified gross noisy pixels and removes events from those pixels and also removes events from flickering pixels and detectors for those specific periods. A bad pixel file with the combined list of bad pixels identified by this module and that from CALDB is also written out along with the cleaned event file.

Parameters

9. cztflagbadpix

Purpose

This module combines bad pixel information from multiple sources, if required. It reads a list of bad pixel files and writes out a single bad pixel file combining the information from all of them. A list of all bad pixels mentioned in the input files is made, and the unique elements in the list are written out.

Parameters

10. cztevtencor

Purpose

This module applies additional gain correction on the event PI values based on the time independant and time-dependant correction factors obtained from analysis of in-flight data. It also optinally removes events below LLD and above ULD.

Parameters

11. cztevtclean

Purpose

This module provides the functionality to select/reject alpha and veto-tagged events in various combinations according to user-supplied choices.

Parameters

12. cztdpigen

Purpose

This module generates detector plane histogram (DPH) and detector plane image (DPI) from clean event file. DPI is obtained by applying effective area correction on the DPH.

Parameters

13. cztimage

Purpose

This module generates sky images from the DPI using Balanced cross-correlation or FFT techniques.

Parameters

14. cztbindata

Purpose

This module generates background subtracted sources spectrum (with response matrix) and light curves for a given source coordinates within the FOV by using mask-weighting tecnique. There is also option to generate total spectrum or light curve including background.

Parameters

15. cztaddspec

Purpose

This module provides functionality to add multiple CZTI spectra together. It is possible to add different quadrant spectra of one observation or add each quadrant spectra of multiple observations.

Parameters

16. cztnoisypixclean

Purpose

This module is part of generalized event selection algorithm that may be used instead of cztpixclean module in default pipeline. It identifies the gross noisy pixels and removes all the events from such pixels. It carried out iterative 5-sigma clipping of noisy pixels, seperately for nominal gain pixels and low gain pixels.

Parameters

17. cztsuperbunchclean

Purpose

This module is part of generalized event selection algorithm that may be used instead of cztpixclean module in default pipeline. It is used to identify post-bunch noises that span different modules. It identifies the bunches with large number of events which causes post bunch noises along the path of the interacted particle. These events are identified by an algorithm (outlined in Paul et al 2021), and those GTIs are removed from further analysis. The livetime file is updated with the newly updated GTI. The threshold file contains the recommended threshold values given in Ratheesh et al 2021b.

Parameters

18. cztheavybunchclean

Purpose

This module is part of generalized event selection algorithm that may be used instead of cztpixclean module in default pipeline. It removes the post bunch noises due to cosmic particles from the genuine X-ray events, based on their properties which differ from the latter. The threshold file contains recommended threshold values given in Ratheesh et al 2021b.

Parameters

19. cztflickpixclean

Purpose

This module is part of generalized event selection algorithm that may be used instead of cztpixclean module in default pipeline. It identifies and flags all the flickering pixels (or noisy pixels at shorter time scales). The identified flickering pixels are updated in the badpix file. It further identfies and removes events from those pixels having counts beyond the Poissonian limit using the DPH at 1 s and 10 s time scales.

Parameters

20. czteventsep

Purpose

This module is part of generalized event selection algorithm that may be used instead of cztpixclean module in default pipeline. It seperates single and double events in an event file.

Parameters