Note
Click here to download the full example code or to run this example in your browser via Binder
Exponential cutoff power law spectral model#
This model parametrises a cutoff power law spectrum.
It is defined by the following equation:
\[\phi(E) = \phi_0 \cdot \left(\frac{E}{E_0}\right)^{-\Gamma} \exp(- {(\lambda E})^{\alpha})\]
Example plot#
Here is an example plot of the model:
from astropy import units as u
import matplotlib.pyplot as plt
from gammapy.modeling.models import ExpCutoffPowerLawSpectralModel, Models, SkyModel
energy_bounds = [0.1, 100] * u.TeV
model = ExpCutoffPowerLawSpectralModel(
amplitude=1e-12 * u.Unit("cm-2 s-1 TeV-1"),
index=2,
lambda_=0.1 * u.Unit("TeV-1"),
reference=1 * u.TeV,
)
model.plot(energy_bounds)
plt.grid(which="both")
YAML representation#
Here is an example YAML file using the model:
components:
- name: exp-cutoff-power-law-model
type: SkyModel
spectral:
type: ExpCutoffPowerLawSpectralModel
parameters:
- name: index
value: 2.0
- name: amplitude
value: 1.0e-12
unit: cm-2 s-1 TeV-1
- name: reference
value: 1.0
unit: TeV
- name: lambda_
value: 0.1
unit: TeV-1
- name: alpha
value: 1.0