CCA Colloquium: Anna Watts

Title: Mapping neutron stars with NICER

Abstract: NICER, the Neutron Star Interior Composition Explorer, is an X-ray telescope that installed on the International Space Station. Its mission is to study the nature of the densest matter in the Universe, found in the cores of neutron stars. NICER uses Pulse Profile Modeling, a technique that exploits relativistic effects on X-rays emitted from the hot magnetic polar caps of millisecond pulsars. The technique also lets us map the hot emitting regions, which form as magnetospheric particles slam into the stellar surface – no mean feat for tiny stars thousands of light years from Earth. I will present NICER’s latest results – including a measurement of the radius of the highest mass pulsar known – and discuss the implications for our understanding of ultradense matter, pulsar emission, and stellar magnetic fields. I will also look ahead to the next generation of X-ray telescopes that will exploit the Pulse Profile Modelling technique to study the properties of accreting stars.