We use the Bayesian approach to write the posterior probability density for the three-dimensional velocity of a pulsar and for its kinematic age .
As a prior , we use the bimodal velocity distribution found in a recent article by Verbunt , Igoshev & Cator ( 2017 ) .
When we compare the kinematic ages with spin-down ages we find that in general they agree with each other .
In particular , maximum likelihood analysis sets the lower limit for the exponential magnetic field decay timescale at 8 Myr with slight preference of t _ { \mathrm { dec } } \approx 12 Myr and compatible with no decay at all .
One of the objects in the study , pulsar B0950+08 has kinematic and cooling ages \approx 2 Myr which is in strong contradiction with its spin-down age \tau \approx 17 Myr .
The 68 per cent credible range for the kinematic age is 1.2–8.0 Myr .
We conclude that the most probable explanation for this contradiction is a combination of magnetic field decay and long initial period .
Further timing , UV and X-ray observations of B0950+08 are required to better constrain its origin and evolution .