Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Strong magnetic fields in normal galaxies at high redshift

Abstract

The origin and growth of magnetic fields in galaxies is still something of an enigma1. It is generally assumed that seed fields are amplified over time through the dynamo effect2,3,4,5, but there are few constraints on the timescale. It was recently demonstrated that field strengths as traced by rotation measures of distant (and hence ancient) quasars are comparable to those seen today6, but it was unclear whether the high fields were in the unusual environments of the quasars themselves or distributed along the lines of sight. Here we report high-resolution spectra that demonstrate that the quasars with strong Mg ii absorption lines are unambiguously associated with larger rotation measures. Because Mg ii absorption occurs in the haloes of normal galaxies7,8,9,10,11 along the sightlines to the quasars, this association requires that organized fields of surprisingly high strengths are associated with normal galaxies when the Universe was only about one-third of its present age.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: FRM distributions for different numbers of strong Mg  ii absorption lines.
Figure 2: Cumulative FRM distributions for sightlines with and without strong Mg  ii absorption line systems.

Similar content being viewed by others

References

  1. Rees, M. J. Origin of cosmic magnetic fields. Astron. Nachr. 327, 395–398 (2006)

    Article  ADS  Google Scholar 

  2. Zel’dovich, Ruzmaikin, A. A. & Sokoloff, D. D. in Magnetic Fields in Astrophysics (ed. Roberts, P. H.) 37–44 (Gordon & Breach, Montreux, 1983)

    Google Scholar 

  3. Kulsrud, R. M. & Zweibel, E. G. On the origin of cosmic magnetic fields. Rep. Prog. Phys. 71 10.1088/0034-4885/71/4/046901 (2008)

  4. Kulsrud, R. M. A critical review of galactic dynamos. Annu. Rev. Astron. Astrophys. 37, 37–64 (1999)

    Article  ADS  Google Scholar 

  5. Parker, E. N. Fast dynamos, cosmic rays, and the Galactic magnetic field. Astrophys. J. 401, 137–145 (1992)

    Article  ADS  Google Scholar 

  6. Kronberg, P. P. et al. A global probe of cosmic magnetic fields to high redshifts. Astrophys. J. 676, 70–79 (2008)

    Article  ADS  CAS  Google Scholar 

  7. Churchill, C. W., Kacprzak, G. G. & Steidel, C. C. in Probing Galaxies through Quasar Absorption Lines (Proc. IAU Colloq. C19) (ed. Roberts, P. H.) 24–41 (Cambridge Univ. Press, Cambridge, UK, 2005)

    Google Scholar 

  8. Nestor, D. B., Turnshek, D. A. & Rao, S. M. Mg II absorption Systems in Sloan Digital Sky Survey QSO spectra. Astrophys. J. 628, 637–654 (2005)

    Article  ADS  CAS  Google Scholar 

  9. Steidel, C. C. in QSO Absorption Lines (Proc. ESO Workshop, Garching, Germany, 21–24 November 1994) (ed. Meylan, G.) 139–152 (Springer, Berlin, 1995)

    Book  Google Scholar 

  10. Zibetti, S. et al. Optical properties and spatial distribution of Mg II absorbers from SDSS image stacking. Astrophys. J. 658, 161–184 (2007)

    Article  ADS  CAS  Google Scholar 

  11. Kacprzak, G. G., Churchill, C. W., Steidel, C. C. & Murphy, M. T. Halo gas cross sections and covering fractions of MgII absorption selected galaxies. Astron. J. 135, 922–927 (2008)

    Article  ADS  Google Scholar 

  12. Bernet, M. L. Cosmic Magnetic Fields at High Redshifts. Diploma thesis, ETH Zürich. (2005)

    Google Scholar 

  13. Kronberg, P. P. & Perry, J. J. Absorption lines, Faraday rotation, and magnetic field estimates for QSO absorption-line clouds. Astrophys. J. 263, 518–532 (1982)

    Article  ADS  CAS  Google Scholar 

  14. Welter, G. L., Perry, J. J. & Kronberg, P. P. The rotation measure of QSOs and of intervening clouds – Magnetic fields and column densities. Astrophys. J. 279, 19–39 (1984)

    Article  ADS  CAS  Google Scholar 

  15. Watson, A. M. & Perry, J. J. QSO absorption lines and rotation measure. Mon. Not. R. Astron. Soc. 248, 58–73 (1991)

    Article  ADS  CAS  Google Scholar 

  16. 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  CAS  Google Scholar 

  17. Dekker, H., D’Odorico, S., Kaufer, A., Delabre, B. & Kotzlowski, H. Design, construction, and performance of UVES, the echelle spectrograph for the UT2 Kueyen Telescope at the ESO Paranal Observatory. Proc. SPIE 4008, 534–545 (2000)

    Article  ADS  Google Scholar 

  18. Kronberg, P. P., Perry, J. J. & Zukowski, E. L. The ‘jet’ rotation measure distribution and the optical absorption system near the z = 1.953 quasar 3C191. Astrophys. J. 355, L31–L34 (1990)

    Article  ADS  Google Scholar 

  19. Han, J. L. et al. Pulsar rotation measure and the large-scale structure of the Galactic magnetic field. Astrophys. J. 642, 868–881 (2006)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  21. Kronberg, P. P., Perry, J. J. & Zukowski, E. L. 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. 387, 528–535 (1992)

    Article  ADS  CAS  Google Scholar 

  22. Rao, S. M., Turnshek, D. A. & Nestor, D. B. Damped Lyα systems at z<1.65: The expanded Sloan Digital Sky Survey Hubble Space Telescope sample. Astrophys. J. 636, 610–630 (2006)

    Article  ADS  CAS  Google Scholar 

  23. Péroux, C., Dessauges-Zavadsky, M., D’Odorico, S., Kim, T. & McMahon, R. G. A homogenous sample of sub-damped Lyman systems – IV. Global metallicity evolution. Mon. Not. R. Astron. Soc. 382, 177–193 (2007)

    Article  ADS  Google Scholar 

  24. Prochaska, J. X. et al. Supersolar super-Lyman limit systems. Astrophys. J. 648, 97–100 (2006)

    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. Beck, R. The role of magnetic fields in spiral galaxies. Astrophys. Space Sci. 289, 293–302 (2004)

    Article  ADS  Google Scholar 

  27. Kronberg, P. P. Extragalactic magnetic fields. Rep. Prog. Phys. 57, 325–382 (1994)

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

Our observations were made on the European Southern Observatory’s telescopes at the Paranal Observatory under programme IDs 075.A-0841 and 076.A-0860. M.L.B. acknowledges financial support from the Swiss National Science Foundation, and P.P.K. acknowledges support from the Natural Sciences and Engineering Council of Canada and the US Department of Energy.

Author Contributions M.L.B. reduced the UVES spectra, identified the Mg ii absorbers in them and carried out the statistical analyses that are presented in the paper. F.M. was the principal investigator on the UVES observational project on the Very Large Telescope and made the observations in Chile. F.M. and S.J.L. oversaw the overall design and execution of the research. P.P.K. derived the FRMs from multifrequency polarization measurements obtained at the NRAO Very Large Array and the Max Planck Institute for Radio Astronomy’s Effelsberg 100-m radio telescope, and other radio telescopes. M.D.–Z. advised on the observation and reduction of the UVES data and the identification of Mg ii absorbers.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Francesco Miniati.

Supplementary information

Supplementary information

The file contains Supplementary Notes and Supplementary Methods. This file contains the following additional information: (a) model used to describe the observed RM data, (b) brief description of the methods used for the statistical analysis. (PDF 180 kb)

Supplementary information

The file contains Supplementary Figure 1. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources, 4C_m05_64, 4C_p05_64, 4C_m04_04, 4C_p11_69, OX_m173, OX_m192, PKS_0112_017, PKS_2227m08, PKS_1615p029) (PDF 7501 kb)

Supplementary information

The file contains Supplementary Figure 2. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. ( Spectrum of sources: PKS_2353m18,PKS_2340m036, MRC_0122m003, 3C_057, 3C_454_3, OB_m094, OC_m065, OC_m192, OX_p057) (PDF 6995 kb)

Supplementary information

The file contains Supplementary Figure 3. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources: PKS_0038m020, PKS_1424m11, PKS_2223m05, PKS_2243m123, PKS_2255m282, 4C_m05_62, OQ_p135, OW_m174, 3C_037) (PDF 7419 kb)

Supplementary information

The file contains Supplementary Figure 4. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources 3C_039, 3C_298, 4C_p06_69, 4C_m03_79, OC_m259, OX_m325, PKS_2204_54, PKS_2326m477, PKS_2353m68.) (PDF 7323 kb)

Supplementary information

The file contains Supplementary Figure 5. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources: 3C_094, 3C_095, 3C_208, 3C_245, 3C_281, 4C_20_24, 4C_m00_50, 4C_m02_55, 4C_m06_35.) (PDF 7564 kb)

Supplementary information

The file contains Supplementary Figure 6. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources: 4C_p01_24, 4C_p02_27, 4C_p06_41, 4C_p13_46, 4C_p19_34, 4C_p19_44, OD_m055, OD_p094_7, OK_186.) (PDF 7566 kb)

Supplementary information

The file contains Supplementary Figure 7. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources: PKS_0130_m17, PKS_0202_m17, PKS_0332_m403, PKS_0402_m362, PKS_0414_m06, PKS_0420_m01, PKS_0422_m380, PKS_0506_m61, PKS_0839_p18,) (PDF 7472 kb)

Supplementary information

The file contains Supplementary Figure 8. This figure shows the spectra of the 71 QSOs used in the analysis, with wavelength ranging from 3760Å to 8560Å. The strong MgII absorption systems are marked with red filled circles above the λr=2796.35,2803.53 lines. (Spectrum of sources: PKS_1111_p149, PKS_1127_m14, PKS_1143_m245, PKS_1157_p014, PKS_1244_m255, PKS_B1419_m272, TXS_0223_p113,) (PDF 6662 kb)

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bernet, M., Miniati, F., Lilly, S. et al. Strong magnetic fields in normal galaxies at high redshift. Nature 454, 302–304 (2008). https://doi.org/10.1038/nature07105

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature07105

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing