# PWN¶

class gammapy.astro.source.PWN(pulsar=<gammapy.astro.source.pulsar.Pulsar object>, snr=<gammapy.astro.source.snr.SNRTrueloveMcKee object>, eta_e=0.999, eta_B=0.001, morphology='Gaussian2D', age=None)[source]

Bases: object

Simple pulsar wind nebula (PWN) evolution model.

Parameters: pulsar : Pulsar Pulsar model instance. snr : SNRTrueloveMcKee SNR model instance eta_e : float Fraction of energy going into electrons. eta_B : float Fraction of energy going into magnetic fields. age : Quantity Age of the PWN. morphology : str Morphology model of the PWN

Methods Summary

 magnetic_field(self, t) Estimate of the magnetic field inside the PWN. radius(self, t) Radius of the PWN at age t.

Methods Documentation

magnetic_field(self, t)[source]

Estimate of the magnetic field inside the PWN.

By assuming that a certain fraction of the spin down energy is converted to magnetic field energy an estimation of the magnetic field can be derived.

Parameters: t : Quantity Time after birth of the SNR
radius(self, t)[source]

Radius of the PWN at age t.

During the free expansion phase the radius of the PWN evolves like:

$R_{PWN}(t) = 1.44 \left(\frac{E_{SN}^3\dot{E}_0^2} {M_{ej}^5}\right)^{1/10}t^{6/5} \text{pc}$

After the collision with the reverse shock of the SNR, the radius is assumed to be constant (See radius_reverse_shock).

Parameters: t : Quantity Time after birth of the SNR