Pulse-to-Pulse Intensity Modulation of Three X-Ray Pulsars Using NICER Data

We studied the X-ray emissions of the pulsars PSR B1937+21, PSR B1821-24, and the Crab pulsar (PSR B0531+21) using the Neutron star Interior Composition Explorer (NICER). We are looking for evidence of non-Gaussian modulation in the intensity of the pulses in order to study their emission mechanisms by conducting a pulse-to-pulse analysis. For PSR B1937+21 and PSR B1821-24 this is the first time that a pulse-by-pulse study has been done in the X-ray regime. We have observed that the pulsars PSR B1937+21 and PSR B1821-24 adhere to a Gaussian distribution of pulse intensities, while the Crab pulsar deviates from a Gaussian distribution.