SSCpol

Python + C codebase to calculate the observed steady-state SED and polarization of a relativistic conical jet of electrons & positrons. Synchrotron and Synchrotron-Self Compton (SSC) Polarization are included.

Developed for Peirson & Romani (2018), Peirson & Romani (2019) & [Peirson, Liodakis & Romani (2022)]; model inspired partly by Potter & Cotter (2012) & TEMZ.

Model free parameters are:

jet power [W],
initial electron power law index,
the electron exponential cutoff energy [eV],
initial magnetic flux density at jet base [T],
bulk Lorentz factor,
observation angle [deg],
jet opening angle [deg],
initial equipartition fraction,
number of random B-field zones in one jet cross section (either 1,7,19,37,61,91,127).

Requirements

Python requirements noted in requirements.txt and automatically installed when running installation.
C requirements are noted in Makefile. (gcc, GSL, CBlas, see https://www.gnu.org/software/gsl/)

Installation

git clone this repository then pip3 install -e . from root directory.

Usage

See notebooks/example.ipynb for common usage.
python3 -u fit.py to run the model fits to Blazar spectra.
See python3 fit.py -h
notebooks/plot_results.ipynb to visualize results and reproduce plots from [Peirson, Liodakis & Romani (2022)]. from sscpol.jet_fns import run_ssc for single model evaluation.

Testing

Once installed run: python3 -m pytest sscpol to execute the test suite.

Attribution

    @article{peirson_polarization_2019,
	title = {The {Polarization} {Behavior} of {Relativistic} {Synchrotron} {Self}-{Compton} {Jets}},
	volume = {885},
	issn = {0004-637X},
	url = {https://doi.org/10.3847%2F1538-4357%2Fab46b1},
	doi = {10.3847/1538-4357/ab46b1},
	language = {en},
	number = {1},
	urldate = {2020-03-28},
	journal = {ApJ},
	author = {Peirson, A. L. and Romani, Roger W.},
	month = nov,
	year = {2019},
	pages = {76},
}

Basic algorithm:

Numbers in paretheses refer to equations in [Peirson & Romani (2019)].