Spectro-temporal Studies of Rapid Transition of the Quasi-periodic Oscillations in the Black Hole Source H1743-322

An appearance or disappearance of quasi-periodic oscillations (QPOs) associated with the variation of X-ray flux can be used to decipher the accretion–ejection mechanism of black hole X-ray sources. We searched for and studied such rapid transitions in H1743-322 using archival data from the Rossi X-ray Timing Explorer and found eight such events, where a QPO vanishes suddenly along with the variation of X-ray flux. The appearance/disappearance of QPOs was associated with four events exhibiting type-B QPOs at ∼4.5 Hz: one was a type-A QPO at ν ∼ 3.5 Hz, and the other three were connected to type-C QPOs at ∼9.5 Hz. Spectral studies of the data revealed that the inner disk radius remained at the same location around 2–9 r g , depending on the model used, but power-law indices were varying, indicating that either a corona or a jet is responsible for the events. The probable ejection radii of coronas were estimated to be around 4.2–15.4 r g based on the plasma ejection model. Our X-ray and quasi-simultaneous radio correlation studies suggest that the type-B QPOs are probably related to the precession of a weak jet, though a small and weak corona is present at its base, and the type-C QPOs are associated with the base of a relatively strong jet, which is acting like a corona.