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Detection of microgauss coherent magnetic fields in a galaxy five billion years ago

Abstract

Magnetic fields play a pivotal role in the physics of interstellar medium in galaxies1, but there are few observational constraints on how they evolve across cosmic time2,3,4,5,6,7. Spatially resolved synchrotron polarization maps at radio wavelengths reveal well-ordered large-scale magnetic fields in nearby galaxies1,8,9 that are believed to grow from a seed field via a dynamo effect10,11. To directly test and characterize this theory requires magnetic field strength and geometry measurements in cosmologically distant galaxies, which are challenging to obtain due to the limited sensitivity and angular resolution of current radio telescopes. Here, we report the cleanest measurements yet of magnetic fields in a galaxy beyond the local volume, free of the systematics traditional techniques would encounter. By exploiting the scenario where the polarized radio emission from a background source is gravitationally lensed by a foreground galaxy at z = 0.439 using broadband radio polarization data, we detected coherent μG magnetic fields in the lensing disk galaxy as seen 4.6 Gyr ago, with similar strength and geometry to local volume galaxies. This is the highest redshift galaxy whose observed coherent magnetic field property is compatible with a mean-field dynamo origin.

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Fig. 1: The 5 GHz total intensity radio contour of the gravitational lensing system CLASS B1152+199 overlaid on the HST F814W image.
Fig. 2: Faraday depth spectra of images A (red) and B (blue) of the gravitational lensing system CLASS B1152+199 computed using the rotation measure synthesis technique, followed by deconvolution using the RM-Clean algorithm50.
Fig. 3: Coherent magnetic field strength (|B c(r B)|) at the galacto-centric radius of image B (r B = 2.6 kpc) in the lensing galaxy.

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References

  1. Beck, R. Magnetic fields in spiral galaxies. Annu. Rev. Astron. Astrophys. 24, 4–61 (2016).

    Article  Google Scholar 

  2. Kronberg, P. P., Perry, J. J. & Zukowski, E. L. H. Discovery of extended Faraday rotation compatible with spiral structure in an intervening galaxy at z=0.395—new observations of PKS 1229–021. Astrophys. J. 386, 528–535 (1992).

    Article  ADS  Google Scholar 

  3. Oren, A. L. & Wolfe, A. M. A Faraday rotation search for magnetic fields in quasar damped LY alpha absorption systems. Astrophys. J. 445, 624–641 (1995).

    Article  ADS  Google Scholar 

  4. Joshi, R. & Chand, H. Dependence of residual rotation measure on intervening Mg II absorbers at cosmic distances. Mon. Not. R. Astron. Soc. 434, 3566–3571 (2013).

    Article  ADS  Google Scholar 

  5. Bernet, M. L., Miniati, F., Lilly, S. J., Kronberg, P. P. & Dessauges-Zavadsky, M. Strong magnetic fields in normal galaxies at high redshift. Nature 454, 302–304 (2008).

    Article  ADS  Google Scholar 

  6. Farnes, J. S., O’Sullivan, S. P., Corrigan, M. E. & Gaensler, B. M. Faraday rotation from magnesium II absorbers toward polarized background radio sources. Astrophys. J. 795, 63–89 (2014).

    Article  ADS  Google Scholar 

  7. Kim, K. S. et al. Faraday rotation measure synthesis of intermediate redshift quasars as a probe of intervening matter. Astrophys. J. 829, 133–155 (2016).

    Article  ADS  Google Scholar 

  8. Beck, R. & Wielebinski, R. in Planets, Stars and Stellar Systems Vol. 5: Galactic Structure and Stellar Populations (eds Oswalt, T. D. & Gilmore, G.) 641–723 (Springer, Dordrecht, the Netherlands, 2013).

  9. Kronberg, P. P. Cosmic Magnetic Fields (Cambridge Univ. Press, Cambridge, 2016).

    Book  Google Scholar 

  10. Ruzmaikin, A. A., Shukurov, A. M. & Sokoloff, D. D. Magnetic Fields of Galaxies (Kluwer, Dordrecht, the Netherlands, 1988).

    Book  MATH  Google Scholar 

  11. Kulsrud, R. M. & Zweibel, E. G. On the origin of cosmic magnetic fields. Rep. Prog. Phys. 71, 046901 (2008).

    Article  ADS  Google Scholar 

  12. Myers, S. T. et al. CLASS B1152+199 and B1359+154: two new lens systems discovered in the cosmic lens all-sky survey. Astrophys. J. 117, 2565–2572 (1999).

    Google Scholar 

  13. Rusin, D. et al. High-resolution observations and mass modeling of the CLASS gravitational lens B1152+199. Mon. Not. R. Astron. Soc. 300, 205–211 (2002).

    Article  ADS  Google Scholar 

  14. Dai, X. & Kochanek, C. S. Differential X-ray absorption and dust-to-gas ratios of the lens galaxies SBS 0909+523, FBQS 0951+2635, and B1152+199. Astrophys. J. 692, 677–683 (2009).

    Article  ADS  Google Scholar 

  15. Toft, S., Hjorth, J. & Burud, I. The extinction curve of the lensing galaxy of B1152+199 at z = 0.44. Astron. Astrophys. 357, 115–119 (2000).

    ADS  Google Scholar 

  16. Dyer, C. C. & Shaver, E. G. On the rotation of polarization by a gravitational lens. Astrophys. J. Lett. 390, L5–L7 (1992).

    Article  ADS  Google Scholar 

  17. Narasimha, D. & Chitre, S. M. Large scale magnetic fields in lens galaxies. J. Korean Astron. Soc. 37, 355–359 (2004).

    Article  ADS  Google Scholar 

  18. Patnaik, A. R., Menten, K. M., Porcas, R. W. & Kemball, A. J. in Gravitational Lensing: Recent Progress and Future Goals (eds Brainerd, T. G. & Kochanek, C. S.) 99–100 (Astronomical Society of the Pacific, San Francisco, CA, 2001).

  19. Brentjens, M. A. & de Bruyn, A. G. Faraday rotation synthesis. Astron. Astrophys. 441, 1217–1228 (2005).

    Article  ADS  Google Scholar 

  20. Sokoloff, D. D. et al. Depolarization and Faraday effects in galaxies. Mon. Not. R. Astron. Soc. 299, 189–206 (1998).

    Article  ADS  Google Scholar 

  21. Rumbaugh, N. et al. Radio monitoring campaigns of six strongly lensed quasars. Mon. Not. R. Astron. Soc. 450, 1042–1056 (2015).

    Article  ADS  Google Scholar 

  22. Brown, J. C. et al. Rotation measures of extragalactic sources behind the southern galactic plane: new insights into the large-scale magnetic field of the inner Milky Way. Astrophys. J. 663, 258–266 (2007).

    Article  ADS  Google Scholar 

  23. Haverkorn, M., Brown, J. C., Gaensler, B. M. & McClure-Griffiths, N. M. The outer scale of turbulence in the magnetoionized galactic interstellar medium. Astrophys. J. 680, 362–370 (2008).

    Article  ADS  Google Scholar 

  24. Gaensler, B. M. et al. The magnetic field of the Large Magellanic Cloud revealed through Faraday rotation. Science 307, 1610–1612 (2005).

    Article  ADS  Google Scholar 

  25. Beck, R., Brandenburg, A., Moss, D., Shukurov, A. & Sokoloff, D. Galactic magnetism: recent developments and perspectives. Annu. Rev. Astron. Astrophys. 34, 155–206 (1996).

    Article  ADS  Google Scholar 

  26. Xu, J. & Han, J. L. Extragalactic dispersion measures of fast radio bursts. Res. Astron. Astrophys. 15, 1629–1638 (2015).

    Article  ADS  Google Scholar 

  27. Masters, K. L. et al. Galaxy Zoo: dust in spiral galaxies. Mon. Not. R. Astron. Soc. 404, 792–810 (2010).

    Article  ADS  Google Scholar 

  28. Shukurov, A. in Mathematical Aspects of Natural Dynamos (eds Dormy, E. A. & Soward, M.) Ch. 7 (CRC Press, Boca Raton, FL, 2007).

  29. Shukurov, A. in Cosmic Magnetic Fields (eds Wielebinski, R. & Beck, R.) 113–135 (Springer Berlin Heidelberg, Berlin, Germany, 2005).

  30. Momcheva, I. G., Williams, K. A., Cool, R. J., Keeton, C. R. & Zabludoff, A. I. A spectroscopic survey of the fields of 28 strong gravitational lenses: the redshift catalog. Astrophys. J. Suppl. 219, 29–61 (2015).

    Article  ADS  Google Scholar 

  31. Arshakian, T. G., Beck, R., Krause, M. & Sokoloff, D. Evolution of magnetic fields in galaxies and future observational tests with the Square Kilometre Array. Astron. Astrophys. 494, 21–32 (2009).

    Article  ADS  Google Scholar 

  32. van der Kruit, P. C. & Freeman, K. C. Galaxy disks. Annu. Rev. Astron. Astrophys. 49, 301–371 (2011).

    Article  ADS  Google Scholar 

  33. Neronov, A. & Vovk, I. Evidence for strong extragalactic magnetic fields from Fermi observations of TeV blazars. Science 328, 73–75 (2010).

    Article  ADS  Google Scholar 

  34. Hanasz, M., Wóltański, D. & Kowalik, K. Global galactic dynamo driven by cosmic rays and exploding magnetized stars. Astrophys. J. 706, L155–L159 (2009).

    Article  ADS  Google Scholar 

  35. McMullin, J. P., Waters, B., Schiebel, D., Young, W. & Golap, K. in Astronomical Data Analysis Software and Systems XVI (eds Shaw, R. A., Hill, F. & Bell D. J.) 127–130 (Astronomical Society of the Pacific, San Francisco, CA, 2007).

  36. Perley, R. A. & Butler, B. J. Integrated polarization properties of 3C48, 3C138, 3C147, and 3C286. Astrophys. J. Suppl. 206, 16–23 (2013).

    Article  ADS  Google Scholar 

  37. Sault, R. J., Teuben, P. J & Wright, M. C. H. in Astronomical Data Analysis Software and Systems IV (eds Shaw, R. A., Payne, H. E. & Hayes, J. J. E.) 433–436 (Astronomical Society of the Pacific, San Francisco, 1995).

  38. Farnsworth, D., Rudnick, L. & Brown, S. Integrated polarization of sources at λ~1 m and new rotation measure ambiguities. Astron. J. 141, 191–219 (2011).

    Article  ADS  Google Scholar 

  39. Sun, X. H. et al. Comparison of algorithms for determination of rotation measure and Faraday structure I. 1100–1400 MHz. Astron. J. 149, 60–73 (2015).

    Article  ADS  Google Scholar 

  40. O’Sullivan, S. P. et al. Complex Faraday depth structure of active galactic nuclei as revealed by broad-band radio polarimetry. Mon. Not. R. Astron. Soc. 412, 3300–3315 (2012).

    Article  Google Scholar 

  41. Akahori, T. & Ryu, D. Faraday rotation measure due to the intergalactic magnetic field II: the cosmological contribution. Astrophys. J. 738, 134–142 (2011).

    Article  ADS  Google Scholar 

  42. Leahy, J. P. Small-scale variations in the galactic Faraday rotation. Mon. Not. R. Astron. Soc. 226, 433–446 (1987).

    Article  ADS  Google Scholar 

  43. Harvey-Smith, L., Madsen, G. J. & Gaensler, B. M. Magnetic fields in large-diameter HII regions revealed by the Faraday rotation of compact extragalactic radio sources. Astrophys. J. 736, 83–95 (2011).

    Article  ADS  Google Scholar 

  44. He, C., Ng, C.-Y. & Kaspi, V. M. The correlation between dispersion measure and X-ray column density from radio pulsars. Astrophys. J. 768, 64–72 (2013).

    Article  ADS  Google Scholar 

  45. Peroux, C., Dessauges-Zavadsky, M., D’Odorico, S., Kim, T. S. & McMahon, R. G. A homogenous sample of sub-damped Lyman α systems—IV. Global metallicity evolution. Mon. Not. R. Astron. Soc. 382, 117–193 (2007).

    Article  Google Scholar 

  46. Wolfe, A. M., Gawiser, E. & Prochaska, J. X. Damped LYα systems. Annu. Rev. Astron. Astrophys. 43, 861–918 (2005).

    Article  ADS  Google Scholar 

  47. Dai, X. & Chen, B. Identifying the lens galaxy B1152+199 as a ghostly damped Lyman alpha system by the Cosmic Origin Spectrograph. Preprint at https://arxiv.org/abs/1612.04848 (2016).

  48. Fletcher, A. in The Dynamic Interstellar Medium: a Celebration of the Canadian Galactic Plane Survey (eds Kothes, R., Landecker, T. L. & Willis, A. G.) 197–210 (Astronomical Society of the Pacific, San Francisco, CA, 2010).

  49. Van Eck, C. L., Brown, J. C., Shukurov, A. & Fletcher, A. Magnetic fields in a sample of nearby spiral galaxies. Astrophys. J. 799, 35–54 (2015).

    Google Scholar 

  50. Heald, G., Braun, R. & Edmonds, R. The Westerbork SINGS survey II. Polarization, Faraday rotation, and magnetic fields. Astron. Astrophys. 503, 409–435 (2009).

    Article  ADS  Google Scholar 

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Acknowledgements

The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities.

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Authors

Contributions

S.A.M. led the VLA proposal and observations, performed the data reduction, analysis and interpretation, and wrote the paper. C.C. and B.M.G. contributed to the VLA proposal and interpretation of the data. O.W. and C.K. contributed to the interpretation of the data from the lensing perspective. P.P.K. and E.Z. contributed to the VLA proposal. A.B. and R.B. contributed to the interpretation of the data. All authors discussed the results, interpretations and presentation of the paper.

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Correspondence to S. A. Mao.

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Mao, S.A., Carilli, C., Gaensler, B.M. et al. Detection of microgauss coherent magnetic fields in a galaxy five billion years ago. Nat Astron 1, 621–626 (2017). https://doi.org/10.1038/s41550-017-0218-x

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