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arXiv · 2406.12477

An atypical low-frequency QPO detected in the hard state of MAXI J1348-630 with $Insight$-HXMT

Xin-Lei Wang·Zhen Yan·Fu-Guo Xie·Jun-Feng Wang·Ren-Yi Ma
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Abstract

Based on the $Insight$-HXMT archival data, we have detected a new atypical low-frequency quasi-periodic oscillation (LFQPO) in the black hole X-ray binary MAXI J1348$-$630. The new LFQPO is detected in all the three instruments of $Insight$-HXMT with a combined significance of 3--5 $\sigma$, covering a wide energy range of 1--100 keV. The fractional root-mean-square (RMS) seems decrease with energy. It exclusively appears in the hard state during both the main and mini outburst, spanning an X-ray intensity range by a factor of 10, and a very narrow hardness range. The frequency of this new type of LFQPO is moderately stable, in the range of 0.08--0.15 Hz. We discussed different models for the LFQPO, and found none is able to explain the observed properties of this new type of LFQPO.

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Xin-Lei Wang, Zhen Yan, Fu-Guo Xie, Jun-Feng Wang, Ren-Yi Ma. 2024-06-18. An atypical low-frequency QPO detected in the hard state of MAXI J1348-630 with $Insight$-HXMT. https://arxiv.org/abs/2406.12477

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