pint.derived_quantities.pulsar_age
- pint.derived_quantities.pulsar_age(f: ~astropy.units.quantity.Quantity, fdot: ~astropy.units.quantity.Quantity, n: int = 3, fo: ~astropy.units.quantity.Quantity = <Quantity 1.e+99 Hz>) -> Unit("yr")[source]
Compute pulsar characteristic age
Return the age of a pulsar given the spin frequency and frequency derivative. By default, the characteristic age is returned (assuming a braking index n =3 and an initial spin frequency \(f_0 \\gg f\)). But n and fo can be set.
- Parameters:
f (astropy.units.Quantity) – pulsar frequency
fdot (astropy.units.Quantity) – frequency derivative \(\\dot f\)
n (int, optional) – braking index (default = 3)
fo (astropy.units.Quantity, optional) – initial frequency \(f_0\)
- Returns:
age – pulsar age in
u.yr- Return type:
- Raises:
astropy.units.UnitsError – If the input data are not appropriate quantities
TypeError – If the input data are not quantities
Notes
Calculates
\[\begin{split}\\tau = \\frac{f}{(n-1)\\dot f}\\left(1-\\left(\\frac{f}{f_0}\\right)^{n-1}\\right)\end{split}\]