Letter | Published:

Relativistic reverberation in the accretion flow of a tidal disruption event

Nature volume 535, pages 388390 (21 July 2016) | Download Citation

Abstract

Our current understanding of the curved space-time around supermassive black holes is based on actively accreting black holes, which make up only ten per cent or less of the overall population. X-ray observations of that small fraction reveal strong gravitational redshifts that indicate that many of these black holes are rapidly rotating1; however, selection biases suggest that these results are not necessarily reflective of the majority of black holes in the Universe2. Tidal disruption events, where a star orbiting an otherwise dormant black hole gets tidally shredded and accreted onto the black hole3, can provide a short, unbiased glimpse at the space-time around the other ninety per cent of black holes. Observations of tidal disruptions have hitherto revealed the formation of an accretion disk and the onset of an accretion-powered jet4,5,6,7,8, but have failed to reveal emission from the inner accretion flow, which enables the measurement of black hole spin. Here we report observations of reverberation9,10,11,12 arising from gravitationally redshifted iron Kα photons reflected off the inner accretion flow in the tidal disruption event Swift J1644+57. From the reverberation timescale, we estimate the mass of the black hole to be a few million solar masses, suggesting an accretion rate of 100 times the Eddington limit or more13. The detection of reverberation from the relativistic depths of this rare super-Eddington event demonstrates that the X-rays do not arise from the relativistically moving regions of a jet, as previously thought5,14.

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References

  1. 1.

    The spin of supermassive black holes. Class. Quant. Grav. 30, 244004 (2013)

  2. 2.

    , , , & A selection effect boosting the contribution from rapidly spinning black holes to the cosmic X-ray background. Mon. Not. R. Astron. Soc. 458, 2012–2023 (2016)

  3. 3.

    Tidal disruption of stars by black holes of 106–108 solar masses in nearby galaxies. Nature 333, 523–528 (1988)

  4. 4.

    et al. Relativistic jet activity from the tidal disruption of a star by a massive black hole. Nature 476, 421–424 (2011)

  5. 5.

    et al. Birth of a relativistic outflow in the unusual gamma-ray transient Swift J164449.3+573451. Nature 476, 425–428 (2011)

  6. 6.

    et al. A possible relativistic jetted outburst from a massive black hole fed by a tidally disrupted star. Science 333, 203–206 (2011)

  7. 7.

    et al. Flows of X-ray gas reveal the disruption of a star by a massive black hole. Nature 526, 542–545 (2015)

  8. 8.

    Tidal disruption of stars by supermassive black holes: status of observations. J. High Energy Astrophys. 7, 148–157 (2015)

  9. 9.

    et al. Broad line emission from iron K- and L-shell transitions in the active galaxy 1H 0707-495. Nature 459, 540–542 (2009)

  10. 10.

    , , & Relativistic iron K X-ray reverberation in NGC 4151. Mon. Not. R. Astron. Soc. 422, 129–134 (2012)

  11. 11.

    et al. Modelling the broad Fe Kα reverberation in the AGN NGC 4151. Mon. Not. R. Astron. Soc. 438, 2980–2994 (2014)

  12. 12.

    , , , & X-ray reverberation around accreting black holes. Astron. Astrophys. Rev. 22, 72 (2014)

  13. 13.

    & The tidal disruption of a star by a massive black hole. Astrophys. J. 346, L13–L16 (1989)

  14. 14.

    , , & Swift J1644+57 gone MAD: the case for dynamically important magnetic flux threading the black hole in a jetted tidal disruption event. Mon. Not. R. Astron. Soc. 437, 2744–2760 (2014)

  15. 15.

    et al. An extremely luminous panchromatic outburst from the nucleus of a distant galaxy. Science 333, 199–202 (2011)

  16. 16.

    & Hyperaccretion during tidal disruption events: weakly bound debris envelopes and jets. Astrophys. J. 781, 82 (2014)

  17. 17.

    et al. A 200-second quasi-periodicity after the tidal disruption of a star by a dormant black hole. Science 337, 949–951 (2012)

  18. 18.

    et al. Discovery of Fe Kα X-ray reverberation around the black holes in MCG-5-23-16 and NGC 7314. Astrophys. J. 767, 121 (2013)

  19. 19.

    et al. Discovery of high-frequency iron K lags in Ark 564 and Mrk 335. Mon. Not. R. Astron. Soc. 434, 1129–1137 (2013)

  20. 20.

    et al. Discovery of a ~2-h high-frequency X-ray QPO and iron Kα reverberation in the active galaxy MS 2254.9−3712. Mon. Not. R. Astron. Soc. 449, 467–476 (2015)

  21. 21.

    et al. Discovery of a relation between black hole mass and soft X-ray time lags in active galactic nuclei. Mon. Not. R. Astron. Soc. 431, 2441–2452 (2013)

  22. 22.

    et al. Observing Mkn 421 with XMM-Newton: the EPIC-PN point of view. Astron. Astrophys. 424, 841–855 (2004)

  23. 23.

    & Powerful radiative jets in supercritical accretion discs around non-spinning black holes. Mon. Not. R. Astron. Soc. 453, 3213–3221 (2015)

  24. 24.

    , & A global three-dimensional radiation magneto-hydrodynamic simulation of super-Eddington accretion disks. Astrophys. J. 796, 106 (2014)

  25. 25.

    , & Efficiency of super-Eddington magnetically-arrested accretion. Mon. Not. R. Astron. Soc. 454, L6–L10 (2015)

  26. 26.

    , , & Slim accretion disks. Astrophys. J. 332, 646–658 (1988)

  27. 27.

    et al. Leaving the innermost stable circular orbit: the inner edge of a black-hole accretion disk at various luminosities. Astron. Astrophys. 521, A15 (2010)

  28. 28.

    & Where is the inner edge of an accretion disk around a black hole? Astrophys. J. 573, 754–763 (2002)

  29. 29.

    et al. XMM-Newton observatory. I: the spacecraft and operations. Astron. Astrophys. 365, L1–L6 (2001)

  30. 30.

    et al. The European Photon Imaging Camera on XMM-Newton: the pn-CCD camera. Astron. Astrophys. 365, L18–L26 (2001)

  31. 31.

    & X-ray reverberation close to the black hole in RE J1034+396. Mon. Not. R. Astron. Soc. 418, 2642–2647 (2011)

  32. 32.

    , , , & Rossi x-ray timing explorer observation of Cygnus X-1. II. Timing analysis. Astrophys. J. 510, 874–891 (1999)

  33. 33.

    , & Calculating time lags from unevenly sampled light curves. Astrophys. J. 777, 24 (2013)

  34. 34.

    et al. Observations of MCG-5-23-16 with Suzaku, XMM-Newton and NuSTAR: disk tomography and Compton hump reverberation. Astrophys. J. 789, 56 (2014)

  35. 35.

    et al. Iron K and Compton hump reverberation in SWIFT J2127.4+5654 and NGC 1365 revealed by NuSTAR and XMM-Newton. Mon. Not. R. Astron. Soc. 446, 737–749 (2015)

  36. 36.

    & On generating power law noise. Astron. Astrophys. 300, 707–710 (1995)

  37. 37.

    , , & Long-term X-ray variability of Swift J1644+57. Mon. Not. R. Astron. Soc. 422, 1625–1639 (2012)

  38. 38.

    & Bayes factors. J. Am. Stat. Assoc. 90, 773–795 (1995)

  39. 39.

    et al. Stellar velocity dispersion measurements in high-luminosity quasar hosts and implications for the AGN black hole mass scale. Astrophys. J. 773, 90 (2013)

  40. 40.

    Reverberation measurements for 17 quasars and the size-mass-luminosity relations in active galactic nuclei. Astrophys. J. 533, 631–649 (2000)

  41. 41.

    et al. The radius-luminosity relationship for active galactic nuclei: the effect of host-galaxy starlight on luminosity measurements. II. The full sample of reverberation-mapped AGNs. Astrophys. J. 697, 160–181 (2009)

  42. 42.

    et al. The low-luminosity end of the radius-luminosity relationship for active galactic nuclei. Astrophys. J. 767, 149 (2013)

  43. 43.

    , , , & Statistics, handle with care: detecting multiple model components with the likelihood ratio test. Astrophys. J. 571, 545–559 (2002)

  44. 44.

    , , , & Unbound debris streams and remnants resulting from the tidal disruptions of stars by supermassive black holes. Preprint at (2015)

  45. 45.

    , , , & General relativistic hydrodynamic simulation of accretion flow from a stellar tidal disruption. Astrophys. J. 804, 85 (2015)

  46. 46.

    , & Soft X-ray temperature tidal disruption events from stars on deep plunging orbits. Astrophys. J. 812, L39 (2015)

  47. 47.

    & Black holes in binary systems: observational appearance. Astron. Astrophys. 24, 337–355 (1973)

  48. 48.

    et al. A reverberation-based mass for the central black hole in NGC 4151. Astrophys. J. 651, 775–781 (2006)

  49. 49.

    , , , & Revealing the X-ray source in IRAS 13224-3809 through flux-dependent reverberation lags. Mon. Not. R. Astron. Soc. 430, 1408–1413 (2013)

  50. 50.

    & On X-ray variability in narrow-line and broad-line active galactic nuclei. Mon. Not. R. Astron. Soc. 343, 164–168 (2003)

  51. 51.

    et al. The closest look at 1H0707-495: X-ray reverberation lags with 1.3 Ms of data. Mon. Not. R. Astron. Soc. 428, 2795–2804 (2013)

  52. 52.

    & Narrow iron K lines in active galactic nuclei: evolving populations? Astrophys. J. 618, L83–L86 (2005)

  53. 53.

    & The unified model of active galactic nuclei. I: non-hidden broad-line region Seyfert 2 and narrow-line Seyfert 1 galaxies. Astrophys. J. 653, 137–151 (2006)

  54. 54.

    et al. A reverberation lag for the high-ionization component of the broad-line region in the narrow-line Seyfert 1 Mrk 335. Astrophys. J. 744, L4 (2012)

  55. 55.

    , , , & The curious time lags of PG 1244+026: discovery of the iron K reverberation lag. Mon. Not. R. Astron. Soc. 439, L26–L30 (2014)

  56. 56.

    , , & A long XMM-Newton observation of an extreme narrow-line Seyfert 1: PG 1244+026. Mon. Not. R. Astron. Soc. 436, 3173–3185 (2013)

  57. 57.

    et al. Simultaneous NuSTAR and XMM-Newton 0.5–80 keV spectroscopy of the narrow-line Seyfert 1 galaxy SWIFT J2127.4+5654. Mon. Not. R. Astron. Soc. 440, 2347–2356 (2014)

  58. 58.

    et al. First high-energy observations of narrow-line Seyfert 1s with INTEGRAL/IBIS. Mon. Not. R. Astron. Soc. 389, 1360–1366 (2008)

  59. 59.

    & Kinematical data on early-type galaxies. VI. Astron. Astrophys. 384, 371–382 (2002)

  60. 60.

    , & The flux-dependent X-ray time lags in NGC 4051. Mon. Not. R. Astron. Soc. 435, 1511–1519 (2013)

  61. 61.

    et al. A revised broad-line region radius and black hole mass for the narrow-line Seyfert 1 NGC 4051. Astrophys. J. 702, 1353–1366 (2009)

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Acknowledgements

E.K. thanks A. Zoghbi, M. C. Miller, F. Tombesi, E. Miller and L. Denby for discussions. E.K. also thanks the Hubble Fellowship Program for support under grant number HST-HF2-51360.001-A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. J.M.M. acknowledges N. Schartel and XMM-Newton for executing target-of-opportunity observations of Swift J1644+57. C.R. acknowledges support from NASA under grant number NNX14AF86G. L.D. thanks J. McKinney for discussions. L.D. acknowledges support from NASA/NSF/TCAN (NNX14AB46G), NSF/XSEDE/TACC (TG- PHY120005) and NASA/Pleiades (SMD-14-5451). This work is based on observations made with XMM-Newton, a European Space Agency (ESA) science mission with instruments and contributions directly funded by ESA member states and the US (NASA) and the Suzaku satellite, a collaborative mission between the space agencies of Japan (JAXA) and the US (NASA).

Author information

Affiliations

  1. Department of Astronomy, University of Maryland, College Park, Maryland 20742, USA

    • Erin Kara
    •  & Chris Reynolds
  2. X-ray Astrophysics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA

    • Erin Kara
  3. Joint Space Science Institute, University of Maryland, College Park, Maryland 20742, USA

    • Erin Kara
    • , Chris Reynolds
    •  & Lixin Dai
  4. Department of Astronomy, University of Michigan, Ann Arbor, Michigan 48103, USA

    • Jon M. Miller
  5. Department of Physics, University of Maryland, College Park, Maryland 20742, USA

    • Lixin Dai

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Contributions

E.K. led the XMM-Newton and Suzaku time lag analysis, simulations, interpretation of the results and manuscript preparation. J.M.M. performed the XMM-Newton spectral analysis and contributed to the interpretation of the results. C.R. developed the analytical toy model for reverberation in a super-Eddington flow and contributed to the interpretation of the results. L.D. had the idea of examining X-ray time lags in a TDE and contributed to the interpretation of the results.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to Erin Kara.

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https://doi.org/10.1038/nature18007

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