Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/grburgess/pynchrotron

Implements synchrotron emission from cooling electrons
https://github.com/grburgess/pynchrotron

astromodels chang-cooper electrons gamma-ray-astronomy grb numerics synchrotron threeml

Last synced: 30 days ago
JSON representation

Implements synchrotron emission from cooling electrons

Awesome Lists containing this project

README 

        
[![Build Status](https://travis-ci.org/grburgess/pynchrotron.svg?branch=master)](https://travis-ci.org/grburgess/pynchrotron)

[![codecov](https://codecov.io/gh/grburgess/pynchrotron/branch/master/graph/badge.svg)](https://codecov.io/gh/grburgess/pynchrotron)

[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3544259.svg)](https://doi.org/10.5281/zenodo.3544259)



# pynchrotron

![alt text](https://raw.githubusercontent.com/grburgess/pynchrotron/master/logo.png)



Implements synchrotron emission from cooling electrons. This is the model used in [Burgess et al (2019)](https://www.nature.com/articles/s41550-019-0911-z?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+natastron%2Frss%2Fcurrent+%28Nature+Astronomy%29&utm_content=Google+Feedfetcher). Please cite if you find this code useful for your research.



* This code gets rid of the need for GSL which was originally relied on for a quick computation of the of the synchrotron kernel which is an integral over a  Bessel function. 

* This code has been ported from GSL and written directly in python as well as accelerated with numba

* An astromodels function is also supplied for direct use in 3ML.



## Usage



```python

import numpy as np

import matplotlib as mpl

import matplotlib.pyplot as plt

%matplotlib inline 



import pynchrotron

```



    /Users/jburgess/.environs/pynchro/lib/python3.7/site-packages/astromodels/core/parameter.py:555: UserWarning: We have set the min_value of K to 1e-99 because there was a postive transform

      warnings.warn('We have set the min_value of %s to 1e-99 because there was a postive transform' % self.path)

    /Users/jburgess/.environs/pynchro/lib/python3.7/site-packages/astromodels/core/parameter.py:555: UserWarning: We have set the min_value of xc to 1e-99 because there was a postive transform

      warnings.warn('We have set the min_value of %s to 1e-99 because there was a postive transform' % self.path)



## Create an astromodels model



```python

model = pynchrotron.SynchrotronNumerical()



model



```



    


  • description: Synchrotron emission from cooling electrions
    • 


  • formula: $  $
    • 


  • parameters: 

      


    • K: 

        


      • value: 1.0
        • 


      • desc: normalization
        • 


      • min_value: 0.0
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 0.1
        • 


      • free: True
        • 


      


      • 


    • B: 

        


      • value: 100.0
        • 


      • desc: energy scaling
        • 


      • min_value: 0.01
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 10.0
        • 


      • free: True
        • 


      


      • 


    • index: 

        


      • value: 3.5
        • 


      • desc: spectral index of electrons
        • 


      • min_value: 2.0
        • 


      • max_value: 6.0
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 0.35000000000000003
        • 


      • free: True
        • 


      


      • 


    • gamma_min: 

        


      • value: 500000.0
        • 


      • desc: minimum electron lorentz factor
        • 


      • min_value: 1.0
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 50000.0
        • 


      • free: False
        • 


      


      • 


    • gamma_cool: 

        


      • value: 90000000.0
        • 


      • desc: cooling time of electrons
        • 


      • min_value: None
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 9000000.0
        • 


      • free: True
        • 


      


      • 


    • gamma_max: 

        


      • value: 100000000.0
        • 


      • desc: minimum electron lorentz factor
        • 


      • min_value: 1000000.0
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 10000000.0
        • 


      • free: False
        • 


      


      • 


    • bulk_gamma: 

        


      • value: 1.0
        • 


      • desc: bulk Lorentz factor
        • 


      • min_value: 1.0
        • 


      • max_value: None
        • 


      • unit: 
        • 


      • is_normalization: False
        • 


      • delta: 0.1
        • 


      • free: False
        • 


      


      • 


    


    • 





## Plot the model



```python

fig, ax = plt.subplots()



ene = np.logspace(1,6,400)



ax.loglog(ene, ene**2 * model(ene))

ax.set_xlabel('energy')

ax.set_ylabel(r'$\nu F_{\nu}$')

```



    Text(0, 0.5, '$\\nu F_{\\nu}$')



![png](demo_files/demo_4_1.png)



```python

fig, ax = plt.subplots()



gamma_min = 500000.



gamma_cool = np.linspace(.1 * gamma_min, 5* gamma_min, 10)



ene = np.logspace(-1,6,400)



for gc in gamma_cool:

    model.gamma_cool = gc

    model.gamma_min = gamma_min

    

    ax.loglog(ene, ene**2 * model(ene))

ax.set_xlabel('energy')

ax.set_ylabel(r'$\nu F_{\nu}$')

```



    Text(0, 0.5, '$\\nu F_{\\nu}$')



![png](demo_files/demo_5_1.png)