Prior and posterior distributions for the projection of the kick velocity on the line of sight (v_∥) and the angle between the spin and kick projections onto the plane of the sky (θ_vχ, ⊥). The green distribution shows the uninformative prior described in Sect. 3. The posterior distribution sampled with our MCMC run is shown in red. Darker (lighter) colors correspond to high (low) density regions. The blue scatter point with error bars indicates the observational constraints where our bi-variate Gaussian likelihood is centered.