This page contains the data and scripts corresponding to the analysis presented in the 2017 HAWC paper in the Astrophysical Journal Observation of the Crab Nebula with the HAWC Gamma-Ray Observatory .
We recommend the use of the threeML/astromodels framework (Vianello et al 2015) with the HAL (HAWC accelerated likelihood) plugin for further analysis. Instructions to install an environment to run the analysis may be found here: https://github.com/henrikef/threeML-analysis-workshop
We have prepared an example analysis script which shows how to fit the energy spectrum of the Crab to a log-parabola shape. The script will also output some plots, such as those shown on the webpage and some others, including a spectral energy density plot, as well as a yml file containing the results of the fit, and a likelihood results fits file which also contains more detailed information such as the covariance matrix of the fit. The analysis is performed in python, and you should be sure to put the data and detector response file in the same directory.
Once you have a working environment, you may download and run the analysis here, by running "python crab_fit_logparabola.py". This (gzipped) tarball contains the analysis script linked to above, as well as the expected output files it produces inside a folder called "results".
Fitting the spectrum to a log parabola: dN/dE∝Eα-βln(E/E0). The best fit results of the analysis will converge to:
- K: 2.54 ± 0.07 × 10-13 TeV-1cm-2s-1
- α: -2.646 ± 0.019
- β: 0.104 ± 0.015