PSR J1740+1000: A Young Pulsar Well Out Of The Galactic Plane

We discuss PSR J1740+1000, one of five pulsars recently discovered in a search of 470 square degrees at 430 MHz during the upgrade of the 305-m Arecibo telescope. The period of 154 ms and period derivative of 2.1 x 10^-14 s/s imply a spin-down age of 114 kyr that is smaller than 95% of all known pulsars. The youth and proximity of this pulsar make it a good candidate for detection at X-ray and gamma-ray energies. Its high Galactic latitude of 20.4 degrees suggests a very high velocity if the pulsar was born in the midplane of the Galaxy and if its kinematic age equals its spindown age. Interstellar scintillations, however, suggest a much lower velocity. We discuss possible explanations for this discrepancy, taking into account (a) possible birth sites away from the midplane; (b) contributions from the unmeasured radial velocity; (c) a kinematic age different from the spin-down age; and (d) biasing of the scintillation velocity by enhanced scattering from the North Polar Spur.