Reproduction package for the paper 'Evidence for a dynamic corona in the short-term time lags of black hole X-ray binary MAXI J1820+070'

This is a basic reproduction package for the paper 'Evidence for a dynamic corona in the short-term time lags of black hole X-ray binary MAXI J1820+070', Bollemeijer et al., 2024, MNRAS, 528, 558-576.

• This reproduction package aims for open science, with the internal API designation of 'Gold'.
• Authors: Niek Bollemeijer, Phil Uttley, Arkadip Basak, Adam Ingram, Jakob van den Eijnden, Kevin Alabarta, Diego Altamirano, Zaven Arzoumanian, Douglas J.K. Buisson, Andrew C. Fabian, Elizabeth Ferrara, Keith Gendreau, Jeroen Homan, Erin Kara, Craig Markwardt, Ronald A. Remillard, Andrea Sanna, James F. Steiner,  Francesco Tombesi, Jingyi Wang, Yanan Wang  and Abderahmen Zoghbi
• Paper DOI: https://doi.org/10.1093/mnras/stad3912
• Arxiv DOI: https://doi.org/10.48550/arXiv.2312.09835
• Published in the Monthly Notices of the Royal Astronomical Society (date of acceptance: 2023/12/12)

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 MAXI_J1820+070.
• We used HEASoft v6.28 with standard reprocessing settings to obtain event lists to make light curves. See paper for details.

Software

• Linux Ubuntu 22.04.
• Jupyter Notebook (7.0.7)
• Programming languages used: Python (3.12.1)
• Python packages used: numpy (1.26.3), matplotlib (3.8.2), scipy (1.12.0),  astropy (6.0.0)

Figures and Tables

• Figures can be reproduced from the ./figures/ folder.
• All material and data used are available as intermediate data products.
• Jupyter notebooks (.ipynb files) can be used to make all figures. Running all cells at once does not work, but you can choose the figure you want to remake and executing the relevant cells will result in those figures.

Intermediate data products

• The light curve arrays that are made in the first few cells of the main Jupyter Notebook can be found in 'datafiles.zip'. 
• The parameters for the Lorentzian fits of the power spectra and the grouping of different observations can be found in 'qpofitsc.txt' and 'obsidsa.txt', respectively, in the same zipped folder.

End-to-End analysis scripts

• The three Jupyter notebooks that have been added can be used to make the figures and reproduce the main results of the paper. Evidence_for_a_dynamic_corona_main.ipynb is about the main body of the paper, Evidence_for_a_dynamic_corona_energy_bands.ipynb is used for a part of the Discussion involving multiple narrow energy bands and Evidence_for_a_dynamic_corona_sim.ipynb is about the simulations described in Appendix A.