Reproduction package for the paper "A broad-band spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8-1613"

This is a reproduction package for the paper 'A broad-band spectral-timing study of QPOs in the bright black hole X-ray binary Swift J1727.8−1613', Bollemeijer et al., 2025, MNRAS, 540, 1394-1411. All plots in the main body of the paper and in Appendix C can be reproduced with this package. This reproduction package aims for open science, with the internal API designation of 'Gold'. Authors: Niek Bollemeijer, Phil Uttley and Bei You Paper DOI: https://doi.org/10.1093/mnras/staf750 Arxiv DOI: https://doi.org/10.48550/arXiv.2505.05060 Published in the Monthly Notices of the Royal Astronomical Society (date of acceptance: 2025/05/06) Raw Data Raw event files for the described NICER observations can be obtained from the HEASARC at https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3browse.pl. Select NICER as the telescope and search for Swift_J1727.8-1613 or MAXI_J1535-571. We used HEASoft v6.33 with reprocessing settings described in the paper. HXMT data for Swift_J1727.8-1613 and MAXI_J1535-571 can be obtained from http://archive.hxmt.cn/ and were reprocessed with HXMTSoft v 2.05. I have included a brief guide to aid with setting up HXMT data analysis, called HXMT_guide.pdf. Software Linux Ubuntu 22.04. Jupyter Notebook (7.0.7) Programming languages used: Python (3.12.2) Python packages used: numpy (1.26.4), matplotlib (3.10.7), scipy (1.12.0), astropy (6.0.0), lmfit (1.3.4), IPython (8.20.0) Figures and Tables Figures used in the paper are found in the /figs/figs_in_paper subdirectory/ Figures made using the code are saved in /figs subdirectory Intermediate data products The NICER data are provided in the form of light curve arrays in the subdirectory /nicer_lc_sepdet_arrays. Numpy arrays for making plots that would take a long time to create, e.g. Figs. 2, 3, 9, 10 and 11 from Bollemeijer et al. 2025 are provided in /plotting arrays. Lists of QPO frequencies per sub observation are provided as well, for both sources and telescopes analysed in the paper. End-to-End analysis scripts Jupyter notebooks (.ipynb files) can be used to make the figures and run the analysis. Python scripts for HXMT and NICER data analysis are provided and are used in the notebooks. NICER_J1727_make_lc_arrays.ipynb enables creating the light curve arrays for NICER. NICER_reppack_paper2.ipynb includes the code to run the NICER analysis on the created light curve arrays. HXMT_separate_detectors_reppack2.ipynb includes the analysis for HXMT data, except for obtaining the ratio between the fundamental and harmonic components of the QPO as explained in paragraph 4.1 of Bollemeijer et al. 2025. findharmonicstrength_hxmt_reppack.ipynb includes the code to calculate the ratio between the fundamental and harmonic components of the QPO in HXMT data. simulations_reppack.ipynb includes the code to simulate broadband noise and QPOs, calculate the waveform and show that our method to reconstruct the waveform is reliable. The code will not be maintained, but is provided for legacy purposes. Any questions can be e-mailed to main author Niek Bollemeijer via niekbollemeijer @ proton.me