2.3 Input Parameters (CLI And Python)

This page documents inputs for:

• CLI: runXstack (Xstack_scripts/Xstack_autoscript.py)

• Python API: Xstack.Xstack.XstackRunner

Required Inputs

CLI

• filelist (positional): text file listing PI files.

Python

• pifile_lst

• arffile_lst

• rmffile_lst

• z_lst

Core Workflow Parameters

CLI argument	Python argument	Meaning	Default
--prefix	prefix	Output file prefix	./results/stacked_
--rsp_weight_method	rspwt_method	Full-response weighting method: SHP, FLX, LMN	SHP
--rsp_proj_gamma	rspproj_gamma	Prior photon index used by SHP projection	2.0
--flux_energy_lo + --flux_energy_hi	int_rng	Integration range for SHP weights (rest-frame keV)	1.0, 2.3 keV
--nthreads	nthreads	CPU threads for shifting/stacking pipeline	10 (CLI), 1 (Python)
--ene_trc	ene_trc	Truncate unreliable low-energy ARF/PI bins below threshold	0.0 / None
--extended	extended	Treat sample as extended sources	False
--same_target	same_target	Stack multiple exposures of one target in observed frame (skip rest-frame/NH/background pre-scaling; use FLX response weighting)	False
--do_cache	do_cache	Save/reuse per-source rest-frame cache files (.rf*)	False

Data And Background Parameters

CLI argument	Python argument	Meaning	Default
(auto from PI header)	bkgpifile_lst	Background PI spectrum list	None
(auto from *.nh)	nh_lst	Galactic NH list	None
(not in CLI)	nh_file	Galactic absorption profile template file	None
--num_bkg_groups	Nbkggrp	Number of groups for background-uncertainty estimation	10
--same_rmf	(preprocessed in CLI loader)	Use one common RMF path for all sources	None

Bootstrap Parameters

CLI argument	Python argument	Meaning	Default
--bootstrap	bootstrap	Enable bootstrap mode	False
--num_bootstrap	num_bootstrap	Number of realizations	10
--bootstrap_portion	bootstrap_portion	Fraction of sources resampled in each realization	1.0

Advanced Python-only Parameters

Python argument	Meaning	Default
srcid_lst	Source IDs stored in output metadata/logging	auto index
sample_rmf	RMF used to define reference grids	first RMF
sample_arf	ARF used for reference input-energy grid	first ARF

Output Files

For non-bootstrap runs, Xstack writes:

• <prefix>pi.fits (stacked PI spectrum)

• <prefix>bkgpi.fits (stacked background PI spectrum)

• <prefix>arf.fits

• <prefix>rmf.fits

• <prefix>fene.fits

• <prefix>runXstack.log

In bootstrap mode, each realization gets an index in the output names.

Stacked FITS outputs include command provenance in header HISTORY cards.

Same-target Mode Notes

When same_target=True:

• rspwt_method is effectively forced to FLX,

• do_cache is ignored,

• output src/bkg AREASCAL, BACKSCAL, CORRSCAL are means of input values,

• a log warning is raised if var(x/mean(x)) is large for these scale keywords.