Neutron stars provide precious information about fundamental interactions of particles, the state of dense matter and physics of high magnetic fields, via a variety of techniques. API faculty use neutron star cooling, neutron star outbursts and oscillations, and radio pulsar studies, among others, to probe this extreme physics. Radio pulsars also probe fundamentals of spacetime and gravity, e.g., via binary pulsars and pulsar timing arrays.
API's strengths in the study of dense matter and physics of high magnetic fields lie both in observational radio and X-ray studies of neutron stars, as well as their theoretical interpretation. The foreseeable future in this field will likely see the reaping of a few key fruits from the long investments made here. Pulsar searches and pulsar timing will find a nanoHertz gravitational wave background and constraint early cosmology. API scientists are leading efforts to measure mass and radius simulataneously for millisecond radio pulsars using the new technique of pulse profile modelling and data from NASA's NICER instrument. NICER was installed on the ISS in 2017 and the first results are about to be released. Accurate mass determinations of neutron stars, and probing their interiors via puls profile modelling, will finally get us the long-sought strict constraints on the neutron star equation of state and physics of strong magnetic fields. At the same time, they will deepen our understanding of their formation and evolution. In recent years, API researchers have made significant advances in measuring the neutron star equation of state and accretion processes by observations across the electromagnetic spectrum.
Massive stars, star birth, galaxy evolution, hot stars, optical/infra-red spectroscopy, stellar winds, internal mixing, binary interaction
Now: RXTE archive, Swift, NICER, NuSTAR, Chandra, XXM-NEWTON, LOFAR, WSRT, Arecibo, GBT, large-scale computing
Future: MeerKAT, LOFAR2.0, SKA, ATHENA, eXTP, STROBE-X