Transitional Dynamics: Unveiling the Coexistence and Interplay of Type-B and Type-C QPOs in MAXI J1348-630

TL;DR

This study analyzes the simultaneous presence and interaction of type-B and type-C QPOs in MAXI J1348-630, revealing their energy-dependent behaviors and competitive dynamics during the 2019 outburst.

Contribution

It provides the first detailed broadband timing analysis showing coexistence and competition between type-B and type-C QPOs in a black hole X-ray binary.

Findings

Type-C QPO dominates in hard X-rays (10-30 keV).

Type-B QPO is more prominent in soft X-rays (1-10 keV).

Emergence of type-C QPO suppresses type-B QPO strength.

Abstract

Based on broadband timing analysis of Insight-HXMT and NICER data from the 2019 outburst of the black hole X-ray binary (BHXRB) MAXI J1348-630, we report the detection of the coexistence and competitive interplay between type-C and type-B quasi-periodic oscillations (QPOs). Specifically, the two QPO types were detected simultaneously but exhibited distinct energy dependencies: the type-C QPO was dominant in the hard X-ray band (10-30 keV), while the type-B QPO was more prominent in the soft X-ray band (1-10 keV). Further analysis reveals that the emergence of the type-C QPO suppresses the strength of the type-B QPO, particularly above 10 keV. Tracking the detailed evolution of these QPOs, we find that the weakening of the type-B QPO coincides with the strengthening of the type-C QPO, indicating a competitive interaction between them. These findings reveal a more complex relationship between type-B and type-C QPOs than previously recognized, suggesting they originate from distinct but interacting physical components within the accretion flow and/or jet, and providing new insights into the dynamics of accretion state transitions.