A Multiwavelength Study of Crab Pulsar

Crab Pulsar PSR J0534+2200 is hosted by a very bright nebula and it is a relatively young pulsar with a characteristic age of a few thousand years. It is a unique pulsar and exhibits many different phenomena. The pulsed component across the rotational phase evolves significantly over the electromagnetic spectrum. It is bright in almost all wavebands, from low-frequency radio to very high energy gamma rays, thus providing enough signal-to-noise ratio for timing studies with a reasonable amount of integration. Along with the normal pulsed component, Crab pulsar emits giant radio pulses that are orders of magnitude larger than the normal pulsed intensity and much narrower in time, down to sub-nanoseconds. Although pulsars are generally known for their timing precision, rivaling some of the best atomic clocks on Earth due to their stable rotation, some exhibit jittery rotations, mostly among the younger population. Crab is one such pulsar, showing rotational irregularities called glitches and timing noise. In my talk, I will present some of the recent results we have obtained from long-term monitoring of Crab Pulsar using AstroSat-CZTI, GMRT, ORT, and Fermi-LAT. I will discuss the methodology we adopted to time-align all the telescopes, the effects of timing noise and its mitigation, and the impact of the interstellar medium, which is dominant at low-frequency observations. I will also talk about the recent results on the analysis of Crab giant pulses.