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arXiv · 2105.12338

NICER uncovers the transient nature of the type-B quasi-periodic oscillation in the black hole candidate MAXI J1348-630

L. Zhang·D. Altamirano·P. Uttley·F. Garcia·M. Mendez·J. Homan·J. F. Steiner·K. Alabarta·D. J. K. Buisson·R. A. Remillard·K. C. Gendreau·Z. Arzoumanian·C. Markwardt·T. E. Strohmayer·J. Neilsen·A. Basak
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Abstract

We present a systematic spectral-timing analysis of a fast appearance/disappearance of a type-B quasi-periodic oscillation (QPO), observed in four 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 ~2 keV, suggesting that the QPO emission is dominated by the hard Comptonised component. During the transition, a change in the relative contribution of the disk and Comptonised emission was observed. The disk flux decreased while the Comptonised 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 disk and Comptonised emission. When the type-B QPO appears, more accretion power is dissipated into the Comptonised region than in the disk. Our spectral fits give a hint that the increased Comptonised emission may come from an additional component that is related to the base of the jet.

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L. Zhang, D. Altamirano, P. Uttley, F. Garcia, M. Mendez, J. Homan, J. F. Steiner, K. Alabarta, D. J. K. Buisson, R. A. Remillard, K. C. Gendreau, Z. Arzoumanian, C. Markwardt, T. E. Strohmayer, J. Neilsen, A. Basak. 2021-05-26. NICER uncovers the transient nature of the type-B quasi-periodic oscillation in the black hole candidate MAXI J1348-630. https://doi.org/10.1093/mnras%2Fstab1553

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