NICER Uncovers the Transient Nature of the Type-B Quasi-periodic Oscillation in the Black Hole Candidate MAXI J1348−63

• Published in: Monthly notices of the Royal Astronomical Society Vol. 505; no. 3
• Main Authors: Zhang, L, Altamirano, D, Uttley, P, Garcia, F, Mendez, M, Homan, J, Steiner, J F, Alabarta, K, Buisson, D J K, Remillard, R A, Gendreau, K C, Arzoumanian, Z, Markwardt, C, Strohmayer, T E, Neilsen, J, Basak, A
• Format: Journal Article
• Language: English
• Published: Goddard Space Flight Center Royal Astronomical Society 31.05.2021
• Subjects: Astronomy
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stab1553

We present a systematic spectral-timing analysis of a fast appearance/disappearance of a type-B quasi-periodic oscillation (QPO),observed in four Neutron Star Interior Composition Explorer(NICER) observations of MAXI J1348−630. By comparing the spectra of the period with and without the type-B QPO, we found that the main difference appears at energy bands above∼2keV,suggesting that the QPO emission is dominated by the hard Comptonized component. During the transition, a change in the relative contribution of the disc and Comptonized emission was observed. The disc flux decreased while the Comptonized flux increased from non-QPO to type-B QPO. However, the total flux did not change too much in the NICER band. Our results reveal that the type-B QPO is associated with a redistribution of accretion power between the disc and Comptonized emission. When the type-B QPO appears, more accretion power is dissipated into the Comptonized region than in the disc. Our spectral fits give a hint that the increased Comptonized emission may come from an additional component that is related to the base of the jet.