تقرير
Intermittent QPO properties of MAXI J1820+070 revealed by Insight-HXMT
| العنوان: | Intermittent QPO properties of MAXI J1820+070 revealed by Insight-HXMT |
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| المؤلفون: | Zhang, P., Soria, R., Zhang, S., Ji, L., Kong, L. D., Chen, Y. P., Zhang, S. N., Chang, Z., Ge, M. Y., Li, J., Liu, G. C., Liu, Q. Z., Ma, X., Peng, J. Q., Qu, J. L., Shui, Q. C., Tao, L., Tian, H. J., Wang, P. J., Yan, J. Z., Zeng, X. Y. |
| المصدر: | A&A 677, A178 (2023) |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics High Energy Physics - Phenomenology |
| مصطلحات موضوعية: | Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology |
| الوصف: | We investigate the dynamical properties of low frequency quasi-periodic oscillations (QPOs) observed from the black hole X-ray binary MAXI J1820+070 during the early part of its 2018 outburst, when the system was in a bright hard state. To this aim, we use a series of observations from the Hard X-ray Modulation Telescope Insight-HXMT, and apply a wavelet decomposition (weighted wavelet Z-transforms) to the X-ray light-curve. We find that the QPO phenomenon is intermittent within each individual observation, with some sub-intervals where the oscillation is strongly detected (high root-mean-square amplitude) and others where it is weak or absent. The average life time of individual QPO segments is ~ 5 oscillation cycles, with a 3 sigma tail up to ~ 20 cycles. There is no substantial difference between the energy spectra during intervals with strong and weak/absent QPOs. We discuss two possible reasons for the intermittent QPO strength, within the precessing jet model previously proposed for MAXI J1820+070. In the rigid precession model, intermittent QPOs are predicted to occur with a coherence Q ~ a few when the disk alignment time-scale is only a few times the precession time-scale. Alternatively, we suggest that changes in oscillation amplitude can be caused by changes in the jet speed. We discuss a possible reason for the intermittent QPO strength, within the precessing jet model previously proposed for MAXI J1820+070: we suggest that changes in oscillation amplitude are caused by changes in the jet speed. We argue that a misaligned, precessing jet scenario is also consistent with other recent observational findings that suggest an oscillation of the Compton reflection component in phase with the QPOs. Comment: 8 pages, 4 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1051/0004-6361/202346309 |
| URL الوصول: | http://arxiv.org/abs/2307.07709 |
| رقم الأكسشن: | edsarx.2307.07709 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1051/0004-6361/202346309 |
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