Astrophysics & Particle Physics-APPC 2026

Pulsars are strongly magnetized neutron stars that rotate and emit beams of electromagnetic radiation from their magnetic poles. The beams sweep across the Earth, creating periodic pulses of radiation detected mostly in radio, but also in the X-ray and gamma-ray ranges. Pulsars are among the most accurate cosmic clocks with rotational periods of milliseconds to seconds.Pulsars result from supernova explosions of massive stars, which leave behind dense remnants with densities greater than nuclear density. Their high rotation and magnetic fields cause particle acceleration and emission along magnetic poles. Certain pulsars, called millisecond pulsars, have been spun up by accretion from a binary companion to their highly stable and rapid rotation periods.Binary pulsars are particularly significant in astrophysics, offering laboratories for the experimental verification of general relativity and gravitational wave emission. The pulses' timing can uncover orbital motions, companion star masses, and gravitational radiation-induced relativistic effects like orbital decays.Superhigh-energy pulsars such as X-ray and gamma-ray pulsars provide knowledge on particle acceleration, magnetospheric physics, and radiation processes in extreme gravitational and magnetic fields. Space telescope observations with Chandra, XMM-Newton, Fermi, and NICER have produced detailed pulse profiles, emission geometry, and surface hotspots.Pulsars are also important for astrophysical studies, such as charting the interstellar medium using dispersion measures, exploring neutron star interior structure, and aiding the detection of gravitational waves through pulsar timing arrays. They are critical to understanding stellar evolution, compact object populations, and high-energy astrophysics phenomena.Through the observation of pulsars, researchers obtain distinctive information regarding the physics of ultra-dense matter, magnetic fields, relativistic processes, and matter behavior under extreme conditions, which makes them among the most fascinating and significant objects in contemporary astrophysics.