# Pulsar#

class gammapy.astro.source.Pulsar(P_0='0.1 s', B='1e10 G', n=3, I=<Quantity 1.e+45 cm2 g>, R=<Quantity 1000000. cm>, age=None, L_0=None)[source]#

Bases: object

Magnetic dipole spin-down pulsar model.

Parameters:
P_0float

Period at birth.

BQuantity

Magnetic field strength at the poles (Gauss).

nfloat

Spin-down braking index.

Ifloat

Moment of inertia.

Rfloat

Methods Summary

 Total energy released by a given time. Spin down luminosity. Magnetic field at polar cap (assumed constant). Rotation period. Period derivative at age t. Characteristic age at real age t.

Methods Documentation

energy_integrated(t)[source]#

Total energy released by a given time.

Time-integrated spin-down luminosity since birth.

$E(t) = \dot{L}_0 \tau_0 \frac{t}{t + \tau_0}$
Parameters:
tQuantity

Time after birth of the pulsar.

luminosity_spindown(t)[source]#

Spin down luminosity.

$\dot{L}(t) = \dot{L}_0 \left(1 + \frac{t}{\tau_0}\right)^{-\frac{n + 1}{n - 1}}$
Parameters:
tQuantity

Time after birth of the pulsar.

magnetic_field(t)[source]#

Magnetic field at polar cap (assumed constant).

$B = 3.2 \cdot 10^{19} (P\dot{P})^{1/2} \text{ Gauss}$
Parameters:
tQuantity

Time after birth of the pulsar.

period(t)[source]#

Rotation period.

$P(t) = P_0 \left(1 + \frac{t}{\tau_0}\right)^{\frac{1}{n - 1}}$
Parameters:
tQuantity

Time after birth of the pulsar.

period_dot(t)[source]#

Period derivative at age t.

P_dot for a given period and magnetic field B, assuming a dipole spin-down.

$\dot{P}(t) = \frac{B^2}{3.2 \cdot 10^{19} P(t)}$
Parameters:
tQuantity

Time after birth of the pulsar.

tau(t)[source]#

Characteristic age at real age t.

$\tau = \frac{P}{2\dot{P}}$
Parameters:
tQuantity

Time after birth of the pulsar.