Are Supershells Powered by Multiple Supernovae? Modeling the Radio Pulsar Population Produced by OB Associations

Traditional searches for radio pulsars have targeted individual small regionssuch as supernova remnants or globular clusters, or have covered largecontiguous regions of the sky. None of these searches has been specificallydirected towards giant supershells, some of which are likely to have beenproduced by multiple supernova (SN) explosions from an OB association. Here weperform a Montecarlo simulation of the pulsar population associated withsupershells powered by multiple SNe. We predict that several tens of radiopulsars could be detected with current instruments associated with the largestGalactic supershells (with kinetic energies >~ 10^{53} ergs), and a few pulsarswith the smaller ones. We test these predictions for some of the supershellswhich lie in regions covered by past pulsar surveys. For the smallersupershells, our results are consistent with the few detected pulsars perbubble. For the giant supershell GSH 242-03+37, we find the multiple SNhypothesis inconsistent with current data at the 95% level. We stress theimportance of undertaking deep pulsar surveys in correlation with supershells.Failure to detect any pulsar enhancement in the largest of them would putserious constraints on the multiple SN origin for them. Conversely, thediscovery of the pulsar population associated with a supershell would allow adifferent/independent approach to the study of pulsar properties.Comment: accepted to ApJ; 17 pages, 2 figures, 1 tabl