Shami Chatterjee (Sydney University)

Much Faster than a Speeding Bullet: Pulsar and Magnetar Velocities - Shami Chatterjee colloquium

ATNF Marsfield Lecture Theatre

Abstract

The high velocities of neutron stars establish stringent constraints
on supernova core collapse and birth kicks, and potentially allow us
to discriminate between magnetic and hydrodynamic kick mechanisms.
Our recent parallax and proper motion measurements with the NRAO Very
Long Baseline Array include a transverse velocity of 1100 +- 100 km/s
for PSR B1508ᄃ, the highest model-independent velocity measured for
a neutron star, which poses significant challenges for simulations of
birth kicks. We have also measured the first proper motion for a
magnetar, XTE J1810-197, and are making further measurements with the
Chandra X-ray Observatory, leading to a test of the role of magnetic
fields in mediating birth kicks. Along with such observational tests
of birth kick mechanisms, precision measurements of the distances and
velocities of neutron stars enable a diverse array of results,
including the location of their birth sites, reference frame ties,
the calibration of Galactic electron density models, and
investigation of the properties of the interstellar medium.