.. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_modeling_gallery_spectral_plot_super_exp_cutoff_powerlaw_4fgl.py: .. _super-exp-cutoff-powerlaw-4fgl-spectral-model: Super Exponential Cutoff Power Law Model used for 4FGL ====================================================== This model parametrises super exponential cutoff power-law model spectrum used for 4FGL. It is defined by the following equation: .. math:: \phi(E) = \phi_0 \cdot \left(\frac{E}{E_0}\right)^{-\Gamma_1} \exp \left( a \left( E_0 ^{\Gamma_2} - E^{\Gamma_2} \right) \right) See Equation (3) in https://arxiv.org/pdf/1902.10045.pdf Example plot ------------ Here is an example plot of the model: .. code-block:: default from astropy import units as u import matplotlib.pyplot as plt from gammapy.modeling.models import ( Models, SkyModel, SuperExpCutoffPowerLaw4FGLSpectralModel, ) energy_range = [0.1, 100] * u.TeV model = SuperExpCutoffPowerLaw4FGLSpectralModel( index_1=1, index_2=2, amplitude="1e-12 TeV-1 cm-2 s-1", reference="1 TeV", expfactor=1e-2, ) model.plot(energy_range) plt.grid(which="both") plt.ylim(1e-24, 1e-10) .. image:: /modeling/gallery/spectral/images/sphx_glr_plot_super_exp_cutoff_powerlaw_4fgl_001.png :class: sphx-glr-single-img YAML representation ------------------- Here is an example YAML file using the model: .. code-block:: default model = SkyModel(spectral_model=model, name="super-exp-cutoff-power-law-4fgl-model") models = Models([model]) print(models.to_yaml()) .. rst-class:: sphx-glr-script-out Out: .. code-block:: none components: - name: super-exp-cutoff-power-law-4fgl-model type: SkyModel spectral: type: SuperExpCutoffPowerLaw4FGLSpectralModel parameters: - {name: amplitude, value: 1.0e-12, unit: cm-2 s-1 TeV-1, min: .nan, max: .nan, frozen: false} - {name: reference, value: 1.0, unit: TeV, min: .nan, max: .nan, frozen: true} - {name: expfactor, value: 0.01, unit: '', min: .nan, max: .nan, frozen: false} - {name: index_1, value: 1.0, unit: '', min: .nan, max: .nan, frozen: false} - {name: index_2, value: 2.0, unit: '', min: .nan, max: .nan, frozen: false} .. _sphx_glr_download_modeling_gallery_spectral_plot_super_exp_cutoff_powerlaw_4fgl.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download :download:`Download Python source code: plot_super_exp_cutoff_powerlaw_4fgl.py ` .. container:: sphx-glr-download :download:`Download Jupyter notebook: plot_super_exp_cutoff_powerlaw_4fgl.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature `Gallery generated by Sphinx-Gallery `_