An extreme pulsar tail protruding from the Frying Pan supernova remnant

Abstract

The Frying Pan (G315.9-0.0) is a radio supernova remnant with a peculiar linear feature (G315.78-0.23) extending 10′ radially outward from the rim of the shell. We present radio imaging and polarization observations obtained from the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array, confirming G315.78-0.23 as a bow-shock pulsar wind nebula (PWN) powered by the young pulsar J1437-5959. This is one of the longest pulsar tails observed in radio and it has a physical extent over 20pc. We found a bow-shock standoff distance of 0.002pc, smallest among similar systems, suggesting a large pulsar velocity over 1000kms -1 and a high Mach number 200. The magnetic field geometry inferred from radio polarimetry shows a good alignment with the tail orientation, which could be a result of high flow speed. There are also hints that the postshock wind has a low magnetization and is dominated by electrons and positrons in energy. This study shows that PWNe can offer a powerful probe of their local environment, particularly for the case of a bow shock where the parent supernova shell is also detected. © 2012. The American Astronomical Society. All rights reserved.