Heartbeat of the Mouse: a Young Radio Pulsar Associated with the Axisymmetric

We report the discovery of PSR J1747−2958, a radio pulsar with period P = 98 ms and dispersion measure DM = 101 cm−3 pc, in a deep observation with the Parkes telescope of the axially-symmetric “Mouse” radio nebula (G359.23−0.82). Timing measurements of the newly discovered pulsar reveal a characteristic age P/2Ṗ = 25 kyr and spin-down luminosity Ė = 2.5×1036 erg s−1. The pulsar (timing) position is consistent with that of the Mouse’s “head”. The distance derived from the DM, ≈ 2 kpc, is consistent with the Mouse’s distance limit from HI absorption, < 5.5 kpc. Also, the X-ray energetics of the Mouse are compatible with being powered by the pulsar. Therefore we argue that PSR J1747−2958, moving at supersonic speed through the local interstellar medium, powers this unusual non-thermal nebula. The pulsar is a weak radio source, with period-averaged flux density at 1374 MHz of 0.25 mJy and luminosity ∼ 1 mJy kpc2. Subject headings: ISM: individual (G359.23−0.82) — pulsars: individual (PSR J1747−2958)