Kicked neutron stars and microlensing

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Due to the large kick velocities with which neutron stars are born in supernovae explosions, their spatial distribution is more extended than that of their progenitor stars. The large scale height of the neutron stars above the disk plane makes them potential candidates for microlensing of stars in the Large Magellanic Cloud. Adopting for the distribution of kicks the measured velocities of young pulsars, we obtain a microlensing optical depth of τ 2 N₁₀ × 10⁻⁸ (where N₁₀ is the total number of neutron stars born in the disk in units of 10¹⁰). The event duration distribution has the interesting property of being peaked at T 60--80 d, but for the rates to be relevant for the present microlensing searches would require N₁₀ 1, a value larger than the usually adopted ones (N₁₀ 0.1--0.2).