Low-frequency quasiperiodic oscillations (LFQPOs) are commonly found in black hole X-ray binaries, and their origin is still under debate. The properties of LFQPOs at high energies (above 30 keV) are closely related to the nature of the accretion flow in the innermost regions, and thus play a crucial role in critically testing various theoretical models. The Hard X-ray Modulation Telescope is capable of detecting emissions above 30 keV, and is therefore an ideal instrument to do so. Here we report the discovery of LFQPOs above 200 keV in the new black hole MAXI J1820+070 in the X-ray hard state, which allows us to understand the behaviours of LFQPOs at hundreds of kiloelectronvolts. The phase lag of the LFQPO is constant around zero below 30 keV, and becomes a soft lag (that is, the high-energy photons arrive first) above 30 keV. The soft lag gradually increases with energy and reaches ~0.9 s in the 150–200 keV band. The detection at energies above 200 keV, the large soft lag and the energy-related behaviours of the LFQPO pose a great challenge for most existing models, but suggest that the LFQPO probably originates from the precession of a small-scale jet.
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The Insight-HXMT data reduction was performed using software available from the Insight-HXMT website (http://www.hxmt.cn/ or http://hxmt.org/). The model fitting of power spectra was completed with XSPEC, which is available from the HEASARC website (https://heasarc.gsfc.nasa.gov/xanadu/xspec/). The phase lag was performed with Stingray (see https://stingray.readthedocs.io/en/latest/index.html).
Motta, S. E. et al. Geometrical constraints on the origin of timing signals from black holes. Mon. Not. R. Astron. Soc. 447, 2059–2072 (2015).
Motta, S. E. Quasi periodic oscillations in black hole binaries. Astron. Nachr. 337, 398 (2016).
Ingram, A. R. & Motta, S. E. A review of quasi-periodic oscillations from black hole X-ray binaries: observation and theory. New Astron. Rev. 85, 101524 (2019).
Tagger, M. & Pellat, R. An accretion-ejection instability in magnetized disks. Astron. Astrophys. 349, 1003–1016 (1999).
Cabanac, C. et al. Variability of X-ray binaries from an oscillating hot corona. Mon. Not. R. Astron. Soc. 404, 738–748 (2010).
Rodriguez, J., Varnière, P., Tagger, M. & Durouchoux, Ph. Accretion-ejection instability and QPO in black hole binaries. I. Observations. Astron. Astrophys. 387, 487–496 (2002).
Varnière, P., Rodriguez, J. & Tagger, M. Accretion-ejection instability and QPO in black-hole binaries. II. Relativistic effects. Astron. Astrophys. 387, 497–506 (2002).
Varnière, P., Tagger, M. & Rodriguez, J. A possible interpretation for the apparent differences in LFQPO types in microquasars. Astron. Astrophys. 545, A40 (2012).
Ingram, A., Done, C. & Fragile, P. C. Low-frequency quasi-periodic oscillations spectra and Lense-Thirring precession. Mon. Not. R. Astron. Soc. 397, L101–L105 (2009).
Veledina, A., Poutanen, J. & Ingram, A. A unified Lense-Thirring precession model for optical and X-ray quasi-periodic oscillations in black hole binaries. Astrophys. J. 778, 165 (2013).
Ingram, A. et al. A quasi-periodic modulation of the iron line centroid energy in the black hole binary H1743-322. Mon. Not. R. Astron. Soc. 461, 1967–1980 (2016).
Ingram, A., van der Klis, M., Middleton, M., Altamirano, D. & Uttley, P. Tomographic reflection modelling of quasi-periodic oscillations in the black hole binary H 1743-322. Mon. Not. R. Astron. Soc. 464, 2979–2991 (2017).
Stevens, A. L. & Uttley, P. Phase-resolved spectroscopy of Type-B quasi-periodic oscillations in GX 339-4. Mon. Not. R. Astron. Soc. 460, 2796–2810 (2016).
de Ruiter, I., van den Eijnden, J., Ingram, A. & Uttley, P. A systematic study of the phase difference between QPO harmonics in black hole X-ray binaries. Mon. Not. R. Astron. Soc. 485, 3834–3844 (2019).
Rodriguez, J. et al. Spectral properties of low-frequency quasi-periodic oscillations in GRS 1915+105. Astrophys. J. 615, 416–421 (2004).
Zhang, S., Lu, F. J., Zhang, S. N. & Li, T. P. Introduction to the hard X-ray modulation telescope. Proc. SPIE 9144, 914421 (2014).
Zhang, S. N. et al. Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite. Sci. China Phys. Mech. Astron. 63, 249502 (2020).
Torres, M. A. P. et al. Dynamical confirmation of a black hole in MAXI J1820+070. Astrophys. J. 882, L21 (2019).
Kawamuro, T. et al. MAXI/GSC detection of a probable new X-ray transient MAXI J1820+070. Astron. Telegr. 11399 (2018).
Uttley, P., Cackett, E. M., Fabian, A. C., Kara, E. & Wilkins, D. R. X-ray reverberation around accreting black holes. Astron. Astrophys. Rev. 22, 72 (2014).
Pahari, M., Neilsen, J., Yadav, J. S., Misra, R. & Uttley, P. Comparison of time/phase lags in the hard state and plateau state of GRS 1915+105. Astrophys. J. 778, 136 (2013).
Yadav, J. S. et al. Astrosat/LAXPC reveals the high-energy variability of GRS 1915+105 in the X class. Astrophys. J. 833, 27 (2016).
Zhang, L. et al. The evolution of the phase lags associated with the type-C quasi-periodic oscillation in GX 339-4 during the 2006/2007 outburst. Astrophys. J. 845, 143–153 (2017).
Casella, P., Belloni, T., Homan, J. & Stella, L. A study of the low-frequency quasi-periodic oscillations in the X-ray light curves of the black hole candidate XTE J1859+226. Astron. Astrophys. 426, 587–600 (2004).
Arévalo, P. & Uttley, P. Investigating a fluctuating-accretion model for the spectral-timing properties of accreting black hole systems. Mon. Not. R. Astron. Soc. 367, 801–814 (2006).
Ingram, A. & van der Klis, M. An exact analytic treatment of propagating mass accretion rate fluctuations in X-ray binaries. Mon. Not. R. Astron. Soc. 434, 1476–1485 (2013).
van den Eijnden, J. et al. Inclination dependence of QPO phase lags in black hole X-ray binaries. Mon. Not. R. Astron. Soc. 464, 2643–2659 (2017).
Atri, P. et al. A radio parallax to the black hole X-ray binary MAXI J1820+070. Mon. Not. R. Astron. Soc. 493, L81–L86 (2020).
Torres, M. A. P. et al. The binary mass ratio in the black hole transient MAXI J1820+070. Astrophys. J. Lett. 893, L37 (2020).
Buisson, D. J. K. et al. MAXI J1820+070 with NuSTAR. I. An increase in variability frequency but a stable reflection spectrum: coronal properties and implications for the inner disc in black hole binaries. Mon. Not. R. Astron. Soc. 490, 1350–1362 (2019).
Kara, E. et al. The corona contracts in a black-hole transient. Nature 565, 198–201 (2019).
Yuan, Y., Blandford, R. D. & Wilkins, D. R. Black hole magnetosphere with small-scale flux tubes. Mon. Not. R. Astron. Soc. 484, 4920–4932 (2019).
Yuan, Y., Spitkovsky, A., Blandford, R. D. & Wilkins, D. R. Black hole magnetosphere with small-scale flux tubes - II. Stability and dynamics. Mon. Not. R. Astron. Soc. 487, 4114–4127 (2019).
Liska, M. et al. Formation of precessing jets by tilted black hole discs in 3D general relativistic MHD simulations. Mon. Not. R. Astron. Soc. 474, L81–L85 (2018).
Lense, J. & Thirring, H. Über den einfluss der eigenrotation der zentralkörper auf die bewegung der planeten und monde nach der Einsteinschen gravitationstheorie. Phys. Z. 19, 156 (1918).
Bright, J. S. et al. An extremely powerful long-lived superluminal ejection from the black hole MAXI J1820+070. Nat. Astron. 4, 697–703 (2020).
Russell, T. D. et al. Disk-jet coupling in the 2017/2018 outburst of the galactic black hole candidate x-ray binary MAXI J1535-571. Astrophys. J. 883, 198 (2019).
Hannikainen, D. C. et al. Revisiting the relativistic ejection event in XTE J1550-564 during the 1998 outburst. Mon. Not. R. Astron. Soc. 397, 569–576 (2009).
Hjellming, R. M. & Rupen, M. P. Episodic ejection of relativistic jets by the X-ray transient GRO J1655 - 40. Nature 375, 464–468 (1995).
Fragile, P. C., Blaes, O. M., Anninos, P. & Salmonson, J. D. Global general relativistic magnetohydrodynamic simulation of a tilted black hole accretion disk. Astrophys. J. 668, 417–429 (2007).
Blandford, R. D. & Znajek, R. L. Electromagnetic extraction of energy from Kerr black holes. Mon. Not. R. Astron. Soc. 179, 433–456 (1977).
Blandford, R. D. & Payne, D. G. Hydromagnetic flows from accretion disks and the production of radio jets. Mon. Not. R. Astron. Soc. 199, 883–903 (1982).
Trushkin, S. A. et al. A flat radio spectrum of MAXI J1820+070. Astron. Telegr. 11439 (2018).
Shidatsu, M. et al. X-ray, optical, and near-infrared monitoring of the new X-ray transient MAXI J1820+070 in the low/hard state. Astrophys. J. 868, 54–64 (2018).
Townsend, A. et al. Optical/X-ray flux decoupling in MAXI J1820+070. Astron. Telegr. 11574 (2018).
Paice, J. A. et al. A black hole X-ray binary at 100 Hz: multiwavelength timing of MAXI J1820+070 with HiPERCAM and NICER. Mon. Not. R. Astron. Soc. 490, L62–L66 (2019).
Yu, W. et al. Detection of optical and X-ray QPOs at similar frequencies in MAXI J1820+070. Astron. Telegr. 11510 (2018).
Yu, W. et al. Further detection of the optical low frequency QPO in the black hole transient MAXI J1820+070. Astron. Telegr. 11591 (2018).
Huang, Y. et al. INSIGHT-HXMT observations of the new black hole candidate MAXI J1535-571: timing analysis. Astrophys. J. 866, 122 (2018).
Liao, J. et al. Background model for the low-energy telescope of Insight-HXMT. J. High. Energy Astrophys. 27, 24 (2020).
Guo, C. et al. The background model of the medium energy X-ray telescope of Insight-HXMT. J. High. Energy Astrophys. 27, 44 (2020).
Liao, J. et al. Background model for the high-energy telescope of Insight-HXMT. J. High. Energ. Astrophys. 27, 14 (2020).
Homan, J. & Belloni, T. The evolution of black hole states. Astrophys. Space Sci. 300, 107–177 (2005).
Remillard, R. A. & McClintock, J. E. X-Ray properties of black-hole binaries. Annu. Rev. Astron. Astrophys. 44, 49–92 (2006).
Done, C., Gierliński, M. & Kubota, A. Modelling the behaviour of accretion flows in X-ray binaries: everything you always wanted to know about accretion but were afraid to ask. Astron. Astrophys. Rev. 15, 1–66 (2007).
Belloni, T. M. & Motta, S. E. in Astrophysics of Black Holes: From Fundamental Aspects to Latest Developments Vol. 440 (ed. Bambi, C.) 61 (Springer, 2016).
Shidatsu, M. et al. X-ray and optical monitoring of state transitions in MAXI J1820+070. Astrophys. J. 874, 183 (2019).
Wang, Y. et al. The evolution of the broadband temporal features observed in the black-hole transient MAXI J1820+070 with Insight-HXMT. Astrophys. J. 896, 33 (2020).
Belloni, T. & Hasinger, G. Variability in the noise properties of Cygnus X-1. Astron. Astrophys. 227, L33–L36 (1990).
Belloni, T., Psaltis, D. & van der Klis, M. A unified description of the timing features of accreting X-ray binaries. Astrophys. J. 572, 392 (2002).
Vaughan, B. A. & Nowak, M. A. X-ray variability coherence: how to compute it, what it means, and how it constrains models of GX 339-4 and Cygnus X-1. Astrophys. J. 474, L43–L46 (1997).
Nowak, M. A., Vaughan, B. A., Wilms, J., Dove, J. B. & Begelman, M. C. Rossi X-ray timing explorer observation of Cygnus X-1. II. Timing analysis. Astrophys. J. 510, 874–891 (1999).
Kajava, J. J. E. et al. X-ray dips and a complex UV/X-ray cross-correlation function in the black hole candidate MAXI J1820+070. Mon. Not. R. Astron. Soc. 488, L18–L23 (2019).
Fragos, T., Tremmel, M., Rantsiou, E. & Belczynski, K. Black hole spin-orbit misalignment in galactic X-ray binaries. Astrophys. J. 719, L79–L83 (2010).
We thank A. Ingram, K. Karpouzas and M. Mendez for useful suggestions. This work made use of the data from the Insight-HXMT mission, a project funded by the China National Space Administration (CNSA) and the Chinese Academy of Sciences (CAS). The Insight-HXMT team acknowledges support from the National Program on Key Research and Development Project (grant no. 2016YFA0400800) from the Ministry of Science and Technology of China (MOST) and the Strategic Priority Research Program of the Chinese Academy of Sciences (grant no. XDB23040400). The authors thank the National Natural Science Foundation of China for support under grant nos. U1838111, U1838115, U1838201, U1838202, 11473027, 11633006, 11673023 and 11733009, the National Key Research and Development Program of China (grant no. 2016YFA0400704) and the Royal Society Newton Funds.
The authors declare no competing interests.
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended Data Fig. 1 Light curve, hardness ratio, LFQPO’s frequency, Q factor and fractional rms of MAXI J1820+070 in the X-ray hard state.
a, Insight-HXMT/HE light curve (35–200 keV) of MAXI J1820+070 in the hard state from MJD 58190 to MJD 58301. b, is the evolution of the hardness ratio (defined as the ratio of the net count rate in the 3.0–10.0 keV to 1.0–3.0 keV bands). Panels c-e, show the evolution of the LFQPO’s frequency, Q factor and fractional rms. Phases A to D are marked in the top panel. The red dashed lines indicate the three typical observations in Extended Data Fig. 3.
Extended Data Fig. 2 LFQPO centroid frequency (left) and fractional rms amplitude (right) as a function of energy for a typical observation (ObsID P0114661003).
The LFQPO rms is calculated in the full frequency range of the PDS. The fractional rms-squared normalization depends on the PDS, and the Lorentzian functions are used to fit the PDS. The green, red and blue points represent LE, ME and HE data, respectively. The gray points indicate the LFQPO rms values from the jet precession model with p = 1.
Extended Data Fig. 3 Frequency-dependent phase-lag spectra and LFQPO phase lags for three typical observations.
The observations are marked with red vertical dashed lines in Extended Data Fig. 1, and their general properties are listed in Supplementary Table 3. The spectra of the three observations continue to soften. a, Frequency-dependent phase-lag spectra in the 67–100 keV band. The vertical dashed lines mark the LFQPO frequency, and the cyan points show the narrow dip-like feature. b, The ‘original’ LFQPO phase lags relative to the 1–2.6 keV band. By averaging the phase lags over the LFQPO frequency range ν ± FWHM/2 in different energy bands, we obtain the ‘original’ LFQPO phase lags as a function of photon energy. c, The ‘intrinsic’ LFQPO phase lags, which are determined using the ‘original’ LFQPO phase lags minus the phase-lag continuum. The average value of data points below the LFQPO frequency (purple points in panel (a)) is used as the phase-lag continuum.
Extended Data Fig. 5 The PDS of MAXI J1820+070 in the 150–200 and 200–250 keV bands with different detectors: NaI and CsI, for ObsID P0114661004.
The power is multiplied by a different factor for plotting clarity.
Extended Data Fig. 6 Insight-HXMT hardness-intensity diagram (HID) (upper) and hardness-rms diagram (HRD) (lower) of MAXI J1820+070.
Each point represents a single Insight-HXMT exposure. Data points during the six phases (A to F) are shown in different symbols. The intensity is the LE count rate in the 1.0–10.0 keV band. The hardness ratio is defined as the ratio of the net count rate in the 3.0–10.0 keV to 1.0–3.0 keV bands. The total fractional rms is calculated in the 0.01–32 Hz frequency range. Arrows show the evolutionary track of the outburst. The black points show the three typical observations used to calculate the LFQPO phase lag (Extended Data Fig. 3).
To test the consistency between Insight-HXMT and NICER, we make the Frequency-dependent time-lag spectrum between 0.7–1 keV and 1–10 keV for ObsID P0114661003 (MJD 58199.5–58200.9). The spectrum is consistent with the result from a quasi-simultaneous NICER observation taken within one day (ObsID 1200120106, see the red spectrum of Fig. 2 in Kara et al.31).
As discussed above, the rms is determined by the amplitude of the light curves, which is a function of v. We change v in the range of (0.01-0.99)c with a step length of 0.01c, and simulate light curve for each v. The rms are calculated from these light curves, so we can obtain the relation between v and the rms. Using the observed rms (~ 10%), the jet speed can be inferred.
Supplementary Tables 1–3.
The LFQPO and its phase lag between different energy bands in MAXI J1820+070. As the relativistic jet precesses around the spin axis of the black hole, the observed light curves are modulated due to Doppler boosting of the jet, and the LFQPOs are generated in this process. The closer to the black hole, X-ray photons with higher energies are emitted from the jet. As the jet precesses, we see higher energy photons earlier than lower energy photons, resulting in the observed longer "soft lag" at higher energies.
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Ma, X., Tao, L., Zhang, SN. et al. Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT. Nat Astron 5, 94–102 (2021). https://doi.org/10.1038/s41550-020-1192-2
Nature Communications (2021)