Pulsar Kicks and Spin Tilts in the Close Double Neutron Stars PSR J0737−3039, PSR B1534+12, and PSR B1913+16

Abstract

In view of the recent measurement of the scintillation velocity for PSR J0737-3039, we examine the complete set of constraints imposed on the pulsar B natal kicks (magnitude and orientation) and predict the most favorable pulsar kick velocity and spin tilt for both isotropic and polar kicks. Our analysis takes into account both currently unknown parameters: the orientation of the orbital plane on the sky (Ω) and the radial component of the systemic velocity (Vr). Assuming that the system's peculiar velocity is entirely due to the second supernova explosion, we find that the system may have crossed the Galactic plane multiple times since the birth of the second neutron star and that the postsupernova peculiar velocity could have been as high as 1200 km s-1. We also confirm the absolute lower and upper limits on the physical parameters derived in our earlier study. For specific combinations of the two unknown parameters Ω and Vr, however, we find much tighter constraints on the presupernova binary configuration and natal kicks imparted to pulsar B, as well as on the age of system. Once Ω is measured in the coming year, it will be straightforward to use the results presented here to further constrain the natal kicks and the spin-tilt predictions. We complete our comprehensive study and derive similar constraints and spin-tilt predictions for PSR B1534+12, for which the only free parameter is Vr. Finally, for PSR B1913+16 we update the progenitor and kick constraints using the measured pulsar spin tilt and allowing for Roche lobe overflow from the progenitor of the pulsar companion.