This repository contains the analysis software and processed data products for Stevens et al. 2018, "A NICER Discovery of a Low-Frequency QPO in the Soft- Intermediate State of MAXI J1535-571", ApJL, 865, L15. If you use this research or software, you must cite the paper.
If you would like to apply this software for your own sources, please get in touch with me! I strongly recommend using Stingray because it has much more functionality and is designed for broader use cases.
-
analyze_all_segments.py
: Computes information about sequential 64 seconds segments of the light curves (e.g., count rate, spectral hardness, rms). -
segment_info.ipynb
: Reads in the file fromanalyze_all_segments.py
to visualize the evolution of different parameters and look for correlations. Makes plots like Figure 1 in the paper. -
power_and_cross.py
: Computes the power spectrum and cross spectrum. -
psd_fitting.ipynb
: Writes scripts to fit the power spectrum to get the centroid and FWHM of the QPO. -
lag-energy.ipynb
: Computes and plots the lag-energy spectrum from the cross spectrum computed in step 3.
The input event lists are in in/
(the local path to those event lists will
vary based on your local data directory structure) and the processed data
products are in the out/
directory. Public NICER data can be downloaded from
HEASARC.
get_total_counts.ipynb
will compute the total number of photon counts for a
set of observations (going off the length of the event list in the FITS header).
nicer_v1.02rbn.rsp
is the NICER response matrix binned up to the energy
resolution used for the lag-energy spectrum (the same as in in/chbinfile.txt
and in/chan_group.txt
).
xcor_tools.py
has helper methods used in the analysis steps.
Copyright (c) 2017-2018 Abigail L. Stevens
The contents of this repository are licensed under a BSD 3-Clause License (Revised). See LICENSE for details, and here for more explanation.