A kiloparsec-scale internal shock collision in the jet of a nearby radio galaxy

Abstract

Jets of highly energized plasma with relativistic velocities are associated with black holes ranging in mass from a few times that of the Sun to the billion-solar-mass black holes at the centres of galaxies1. A popular but unconfirmed hypothesis to explain how the plasma is energized is the ‘internal shock model’, in which the relativistic flow is unsteady2. Faster components in the jet catch up to and collide with slower ones, leading to internal shocks that accelerate particles and generate magnetic fields3. This mechanism can explain the variable, high-energy emission from a diverse set of objects4,5,6,7, with the best indirect evidence being the unseen fast relativistic flow inferred to energize slower components in X-ray binary jets8,9. Mapping of the kinematic profiles in resolved jets has revealed precessing and helical patterns in X-ray binaries10,11, apparent superluminal motions12,13, and the ejection of knots (bright components) from standing shocks in the jets of active galaxies14,15. Observations revealing the structure and evolution of an internal shock in action have, however, remained elusive, hindering measurement of the physical parameters and ultimate efficiency of the mechanism. Here we report observations of a collision between two knots in the jet of nearby radio galaxy 3C 264. A bright knot with an apparent speed of (7.0 ± 0.8)c, where c is the speed of light in a vacuum, is in the incipient stages of a collision with a slower-moving knot of speed (1.8 ± 0.5)c just downstream, resulting in brightening of both knots—as seen in the most recent epoch of imaging.

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Figure 1: A comparison of HST images of the jet in 3C 264 from 1994 to 2014.
Figure 2: Position versus time for knots B and C.
Figure 3: Change in optical flux at 6,000 Å in the colliding knots B and C over 20 years.

References

  1. 1

    Livio, M. Astrophysical jets: a phenomenological examination of acceleration and collimation. Phys. Rep. 311, 225–245 (1999).

    ADS  Article  Google Scholar 

  2. 2

    Rees, M. J. The M87 jet—internal shocks in a plasma beam. Mon. Not. R. Astron. Soc. 184, 61–65 (1978).

    ADS  Article  Google Scholar 

  3. 3

    Medvedev, M. V. & Loeb, A. Generation of magnetic fields in the relativistic shock of gamma-ray burst sources. Astrophys. J. 526, 697–706 (1999).

    ADS  Article  Google Scholar 

  4. 4

    Paczynski, B. & Xu, G. Neutrino bursts from gamma-ray bursts. Astrophys. J. 427, 708–713 (1994).

    CAS  ADS  Article  Google Scholar 

  5. 5

    Rees, M. J. & Meszaros, P. Unsteady outflow models for cosmological gamma-ray bursts. Astrophys. J. 430, L93–L96 (1994).

    ADS  Article  Google Scholar 

  6. 6

    Fender, R. P., Belloni, T. M. & Gallo, E. Towards a unified model for black hole X-ray binary jets. Mon. Not. R. Astron. Soc. 355, 1105–1118 (2004).

    CAS  ADS  Article  Google Scholar 

  7. 7

    Spada, M., Ghisellini, G., Lazzati, D. & Celotti, A. Internal shocks in the jets of radio-loud quasars. Mon. Not. R. Astron. Soc. 325, 1559–1570 (2001).

    ADS  Article  Google Scholar 

  8. 8

    Fomalont, E. B., Geldzahler, B. J. & Bradshaw, C. F. Scorpius X-1: the evolution and nature of the twin compact radio lobes. Astrophys. J. 558, 283–301 (2001).

    ADS  Article  Google Scholar 

  9. 9

    Migliari, S., Fender, R. & Méndez, M. Iron emission lines from extended X-ray jets in SS 433: reheating of atomic nuclei. Science 297, 1673–1676 (2002).

    CAS  ADS  Article  Google Scholar 

  10. 10

    Abell, G. O. & Margon, B. A kinematic model for SS433. Nature 279, 701–703 (1979).

    ADS  Article  Google Scholar 

  11. 11

    Hjellming, R. M. & Rupen, M. P. Episodic ejection of relativistic jets by the X-ray transient GRO J1655 − 40. Nature 375, 464–468 (1995).

    CAS  ADS  Article  Google Scholar 

  12. 12

    Mirabel, I. F. & Rodríguez, L. F. A superluminal source in the Galaxy. Nature 371, 46–48 (1994).

    ADS  Article  Google Scholar 

  13. 13

    Dhawan, V., Mirabel, I. F. & Rodríguez, L. F. AU-scale synchrotron jets and superluminal ejecta in GRS 1915+105. Astrophys. J. 543, 373–385 (2000).

    ADS  Article  Google Scholar 

  14. 14

    Cheung, C. C., Harris, D. E. & Stawarz, Ł. Superluminal radio features in the M87 jet and the site of flaring TeV gamma-ray emission. Astrophys. J. 663, L65–L68 (2007).

    CAS  ADS  Article  Google Scholar 

  15. 15

    Marscher, A. P. et al. Probing the inner jet of the quasar PKS 1510–089 with multi-waveband monitoring during strong gamma-ray activity. Astrophys. J. 710, L126–L131 (2010).

    ADS  Article  Google Scholar 

  16. 16

    Crane, P. et al. Discovery of an optical synchrotron jet in 3C 264. Astrophys. J. 402, L37–L40 (1993).

    ADS  Article  Google Scholar 

  17. 17

    Baum, S. A. et al. HST and Merlin observations of 3C 264—a laboratory for jet physics and unified schemes. Astrophys. J. 483, 178–193 (1997).

    ADS  Article  Google Scholar 

  18. 18

    Perlman, E. S. et al. A multi-wavelength spectral and polarimetric study of the jet of 3C 264. Astrophys. J. 708, 171–187 (2010).

    CAS  ADS  Article  Google Scholar 

  19. 19

    Lara, L., Giovannini, G., Cotton, W. D., Feretti, L. & Venturi, T. The inner kiloparsec of the jet in 3C 264. Astron. Astrophys. 415, 905–913 (2004).

    ADS  Article  Google Scholar 

  20. 20

    Biretta, J. A., Sparks, W. B. & Macchetto, F. Hubble Space Telescope observations of superluminal motion in the M87 jet. Astrophys. J. 520, 621–626 (1999).

    ADS  Article  Google Scholar 

  21. 21

    Meyer, E. T. et al. Optical proper motion measurements of the M87 jet: new results from the Hubble Space Telescope. Astrophys. J. 774, L21 (2013).

    ADS  Article  Google Scholar 

  22. 22

    Stawarz, Ł. et al. Dynamics and high-energy emission of the flaring HST-1 knot in the M 87 jet. Mon. Not. R. Astron. Soc. 370, 981–992 (2006).

    CAS  ADS  Article  Google Scholar 

  23. 23

    Lara, L. et al. The radio-optical jet in NGC 3862 from parsec to subkiloparsec scales. Astrophys. J. 513, 197–206 (1999).

    ADS  Article  Google Scholar 

  24. 24

    Kobayashi, S., Piran, T. & Sari, R. Can internal shocks produce the variability in gamma-ray bursts? Astrophys. J. 490, 92–98 (1997).

    ADS  Article  Google Scholar 

  25. 25

    Sparks, W. B., Baum, S. A., Biretta, J., Macchetto, F. D. & Martel, A. R. Face-on dust disks in galaxies with optical jets. Astrophys. J. 542, 667–672 (2000).

    ADS  Article  Google Scholar 

  26. 26

    Goffe, W. L., Ferrier, G. D. & Rogers, J. Global optimization of statistical functions with simulated annealing. J. Econ. 60, 65–99 (1994).

    Article  Google Scholar 

  27. 27

    Harris, D. E. & Krawczynski, H. X-ray emission processes in radio jets. Astrophys. J. 565, 244–255 (2002).

    ADS  Article  Google Scholar 

  28. 28

    Krist, J. E., Hook, R. N. & Stoehr, F. 20 years of Hubble Space Telescope optical modeling using Tiny Tim, Proc. SPIE 8127 (2001).

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Acknowledgements

E.T.M. acknowledges HST grant GO-13327.

Author information

Affiliations

Authors

Contributions

E.T.M. performed the HST data analysis and wrote the paper. B.S., J.A., R.P.v.d.M. and S.T.S. were consulted on and contributed to the HST data analysis. M.G. contributed to the interpretation and performed the theoretical calculations in consultation with E.T.M. E.P. contributed radio data. J.B., C.N. and M.C. provided insight into the design of the observations and interpretation. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Eileen T. Meyer.

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Competing interests

The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 Position versus year for knot A.

Positions are taken from the contour analysis method. Errors are 1σ from contour-derived position measurement added to the systematic error on the mean position from the image registration in quadrature. Source data

Extended Data Figure 2 Position versus year for knot D.

Positions are taken from the contour analysis method. Errors are 1σ from contour-derived position measurement added to the systematic error on the mean position from the image registration in quadrature. Source data

Extended Data Figure 3 Mean flux along the midline of the jet.

Flux is averaged transversely over 0.1″ at each step along the jet. The epoch is denoted by arrows. Note the decay of knot A with time, while the knot B+C complex appears substantially brighter in the last epoch.

Extended Data Figure 4 Comparison of 1983 VLA midline flux to 1994 HST midline flux.

Flux is averaged transversely over 0.1″ at each step along the jet. We fit parabolic forms to the peaks seen in the radio contour to derive rough estimates of knot location, with values depicted with short dashed lines. Dotted lines connecting matched knots are shown to guide the eye.

Extended Data Figure 5 Comparison of 1983 radio positions of knots with HST data.

The locations of knots B and C in 1983 are denoted by triangles, and we include an estimated 15 mas error on the position based on a typical centroiding error of 10% of the beam size (0.15″). Optical data are identical to that described in Fig. 2. For knot C, a dashed line gives the fit to epochs 1983 and 1994. For knot B, the dashed line is a parabolic fit to all data. The location of knot A is noted with a dotted line. Source data

Extended Data Figure 6 Depiction of background subtraction method.

a, The final 2014 image stack before subtraction. b, The mask used in modelling the galaxy and dust disk. (White areas were not used in fits.) c, The final 2014 galaxy and dust model. d, The same image as a after c has been subtracted. Physical scaling of all images and flux scaling of a, b and d are identical.

Extended Data Figure 7 Depiction of modelling results.

a, The resulting background-subtracted model image for the 2002 epoch. b, The real background-subtracted 2002 image. In both cases the image box is shown by the red outline. Only pixels within this area were used in the fit.

Extended Data Table 1 Maximum-likelihood modelling results

Supplementary information

Motion of the knots in 3C 264 from 1994 – 2014

These images correspond to the panels in Figure 1. Contours correspond to the 30% flux-overbackground level. Background galaxy light has been subtracted and the jet rotated into a horizontal position. Knot B, with an apparent speed of 7c, is highlighted in red. (MP4 124 kb)

Motion of the knots in 3C 264 from 1994 – 2014

No contours are plotted to allow an unobstructed view of the jet, which is shown in its native orientation with North up. (MP4 64 kb)

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Meyer, E., Georganopoulos, M., Sparks, W. et al. A kiloparsec-scale internal shock collision in the jet of a nearby radio galaxy. Nature 521, 495–497 (2015). https://doi.org/10.1038/nature14481

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