Special Astrophysics Seminar

Quasi-Periodic Oscillations in high magnetic field X-ray pulsars

Ramanpreet Kaur

Aryabhatta Research Institute of Observational Science

In the transient high magnetic field X-ray pulsars, it is assumed that the accretion disk is formed during outburst, and that the presence of inhomogeneities in the inner accretion disk gives rise to Quasi periodic Oscillations (QPOs). Thus, QPOs are quite rare and are usually found only for a small duration during the outburst in these X-ray pulsars. The evolution of QPOs with X-ray flux and spin period derivative gives us a chance to test the present understanding of QPO formation mechanisms in the X-ray pulsars. In this regard, I will talk about the highest frequency QPOs discovered in high mass X-ray binary pulsars, and a study of QPO evolution in 4U 1626-67 over a period of ~ 22 years.