| Abstract : | Fermi-LAT has led to a golden era of γ-ray pulsars with more than 270 detections in the last couple of decades, fostering several population studies of γ-ray pulsars leading to a LAT picture of the pulsar magnetosphere. However, similar studies of non-thermal X-ray pulsations are lacking due to the unavailability of sensitive instruments. These pulsars are weak emitters in the hard X-ray bands and require substantial exposure times to detect pulsations. The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat is an open detector above 100~keV and facilitates long integrations irrespective of the spacecraft pointing. A custom algorithm utilizes this property to recover hard X-ray pulsations of LAT-timed pulsars from the archival CZTI data (Anusree et al. 2021). The recent inclusion of some of the previously ignored CZTI pixels post-re-calibration allows the construction of pulse profiles up to 1~MeV. Though the limited count rates preclude detailed spectroscopy, a reasonable estimation of the power-law index of the radiation spectrum of off-axis pulsars is possible with the AstroSat mass model simulations (Anusree et al. 2022). This paper consolidates the results of our analyses of about 30~mega-seconds of CZTI data spanning ~6 years to obtain hard X-ray pulsations of selected γ-ray pulsars. We gather a sample of 19 pulsars observed in γ-rays and have a distinct non-thermal emission component in their X-ray spectra and present hard X-ray characteristics for each of them based on our analysis, such as profiles up to sub-MeV CZTI bands and approximations of spectral slopes. We review the high-energy observational studies of these pulsars and compare them with general characteristics emerging from X-rays and γ-rays. We conclude that γ-ray pulsars appear usually pulsed in hard X-rays with double or multiple peaked morphologies with a large variety of spectral slopes in the 80-200~keV CZTI band within the range 0.7-2.1. |
