Evolution of QPOs in GX 339-4 and EXO 1846-031 with Insight-HXMT and NICER

Zuobin Zhang, Honghui Liu, Divya Rawat, Cosimo Bambi, Ranjeev Misra, Pengju Wang, Long Ji, Shu Zhang, Shuangnan Zhang

Published 2023-05-29Version 1

We conduct a spectral and timing analysis of GX 339-4 and EXO 1846-031 with the aim of studying the evolution of Type-C QPOs with spectral parameters. The high cadence data from Insight-HXMT and NICER allow us to track them. Type-C QPOs appear at the end of low-hard state and/or hard-intermediate state. The results reveal that the QPO frequency is closely related to the inner disk radius and mass accretion rate in the two sources. Such a correlation is nicely consistent with the dynamic frequency model.