AstroSat timing analysis of the Crab Pulsar (PSR J0534+2200)

Pulsars are highly magnetised rotating neutron stars, whose radiation is detected in the form of pulses as its magnetic poles cross the line of sight to earth. About 6% of the known pulsars exhibit a rare phenomenon called “pulsar glitch”. Glitches are sudden increases in the rotational frequency of pulsars, whose origin is usually attributed to the internal structure and composition of the neutron star. The Crab pulsar is one among the very few frequent glitching pulsars that exhibits glitches of different amplitudes. Additionally, the Crab pulsar is one of the well studied brightest pulsars often used for calibration of X-ray telescopes in space. We present the results of the timing analysis for the Crab pulsar using AstroSat LAXPC data in the energy range 3-80 keV. AstroSat is India’s first Multi-wavelength satellite, contributing significantly to various investigations of celestial sources since September 28, 2015. Here, we report a new outcome from the AstroSat observations, that is, the detection of the largest glitch observed in the Crab pulsar, marking the first such detection using AstroSat.