Stingray and Spectral Timing: A Brief Introduction¶
Stingray is a Python library designed to perform times series analysis and related tasks on astronomical light curves. It supports a range of commonly-used Fourier analysis techniques, as well as extensions for analyzing pulsar data, simulating data sets, and statistical modelling. Stingray is designed to be easy to extend, and easy to incorporate into data analysis workflows and pipelines.
For a brief overview of the history and state-of-the-art in spectral timing, and for more information about the design and capabilities of Stingray, please refer to Huppenkothen et al. (2019).
Features¶
Current Capabilities¶
Currently implemented functionality in this library comprises:
loading event lists from fits files of a few missions (RXTE/PCA, NuSTAR/FPM, XMM-Newton/EPIC, NICER/XTI)
constructing light curves from event data, various operations on light curves (e.g. addition, subtraction, joining, and truncation)
Good Time Interval operations
power spectra in Leahy, rms normalization, absolute rms and no normalization
averaged power spectra
dynamical power spectra
maximum likelihood fitting of periodograms/parametric models
(averaged) cross spectra
coherence, time lags
cross correlation functions
RMS spectra and lags (time vs energy, time vs frequency); needs testing
covariance spectra; needs testing
bispectra; needs testing
(Bayesian) quasi-periodic oscillation searches
simulating a light curve with a given power spectrum
simulating a light curve from another light curve and a 1-d (time) or 2-d (time-energy) impulse response
simulating an event list from a given light curve _and_ with a given energy spectrum
pulsar searches with Epoch Folding, \(Z^2_n\) test
Future Plans¶
We welcome feature requests: if you need a particular tool that’s currently not available or have a new method you think might be usefully implemented in Stingray, please get in touch!
Other future additions we are currently implementing are:
bicoherence
phase-resolved spectroscopy of quasi-periodic oscillations
Fourier-frequency-resolved spectroscopy
power colours
full HEASARC-compatible mission support
pulsar searches with \(H\)-test
binary pulsar searches
Platform-specific issues¶
Windows uses an internal 32-bit representation for int
. This might create numerical errors when using large integer numbers (e.g. when calculating the sum of a light curve, if the lc.counts
array is an integer).
On Windows, we automatically convert the counts
array to float. The small numerical errors should be a relatively small issue compare to the above.
Presentations¶
Members of the Stingray team have given a number of presentations which introduce Stingray. These include: - 2nd Severo Ochoa School on Statistics, Data Mining, and Machine Learning (2021) - 9th Microquasar Workshop (2021) - European Week of Astronomy and Space Science (2018) - ADASS (Astronomical Data Analysis Software and Systems; meeting 2017, proceedings 2020) - AAS 16th High-Energy Astrophysics Division meeting (2017) - European Week of Astronomy and Space Science 2017 - Python in Astronomy (2016)