Decapitating the Duck: The (Non)Association of PSR B1757−24 and Supernova Remnant G5.4−1.2

Abstract

We have made the first direct interferometric proper-motion measurements of the radio pulsar PSR B1757-24, which sits at the tip of the ``beak'' of the putative ``Duck'' supernova remnant. The peculiar morphology of this radio complex has been used to argue alternately that the pulsar's space motion was either surprisingly high or surprisingly low. In fact, we show that the pulsar's motion is so small that it and its associated nonthermal nebula G5.27-0.9 (the ``head'') are almost certainly unrelated to the much larger G5.4-1.2 (the ``wings'').