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The cosmic microwave background radiation temperature at a redshift of 2.34

Nature volume 408, pages 931–935 (2000)Cite this article

Abstract

The existence of the cosmic microwave background radiation is a fundamental prediction of hot Big Bang cosmology, and its temperature should increase with increasing redshift. At the present time (redshift z = 0), the temperature has been determined with high precision to be TCMBR(0) = 2.726 ± 0.010 K. In principle, the background temperature can be determined using measurements of the relative populations of atomic fine-structure levels, which are excited by the background radiation. But all previous measurements have achieved only upper limits, thus still formally permitting the radiation temperature to be constant with increasing redshift. Here we report the detection of absorption lines from the first and second fine-structure levels of neutral carbon atoms in an isolated cloud of gas at z = 2.3371. We also detected absorption due to several rotational transitions of molecular hydrogen, and fine-structure lines of singly ionized carbon. These constraints enable us to determine that the background radiation was indeed warmer in the past: we find that TCMBR(z = 2.3371) is between 6.0 and 14 K. This is in accord with the temperature of 9.1 K predicted by hot Big Bang cosmology.

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Figure 1: A sample of H2 and C0 absorption lines at zabs = 2.33771.
Figure 2: A sample of heavy-element absorption lines at zabs = 2.33771.
Figure 3: The hydrogen density as a function of kinetic temperature in the zabs = 2.33771 cloud.
Figure 4: Cosmic microwave background temperature as a function of kinetic temperature of the gas.
Figure 5: Measurements of the cosmic microwave background radiation temperature at various redshifts.

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References

  1. Alpher, R. A., Bethe, H. A. & Gamov, G. Evolution of chemical elements. Phys. Rev. 73, 803–804 (1948).

    Article  ADS  CAS  Google Scholar 

  2. Penzias, A. A. & Wilson, R. A measurement of excess antenna temperature at 4080 Mc/s. Astrophys. J. 142, 419–421 (1965).

    Article  ADS  Google Scholar 

  3. Mather, J. C. et al. Measurement of the cosmic microwave background spectrum by the COBE FIRAS instrument. Astrophys. J. 420, 439–444 (1994).

    Article  ADS  Google Scholar 

  4. Bahcall, J. N., Joss, P. C. & Lynds, R. On the temperature of the microwave background radiation at a large redshift. Astrophys. J. 182, L95–L98 (1973).

    Article  ADS  CAS  Google Scholar 

  5. Meyer, D. M., Black, J. H., Chaffee, F. H., Foltz, C. B. & York, D. G. An upper limit on the microwave background temperature at z = 1.776. Astrophys. J. 308, L37–L41 (1986).

    Article  ADS  CAS  Google Scholar 

  6. Songaila, A. et al. Measurement of the microwave background temperature at a redshift of 1.776. Nature 371, 43–45 (1994).

    Article  ADS  Google Scholar 

  7. Songaila, A., Cowie, L. L., Hogan, C. & Rugers, M. Deuterium abundance and background radiation temperature in high redshift primordial clouds. Nature 368, 599–604 (1994).

    Article  ADS  CAS  Google Scholar 

  8. Lu, L., Wargent, W. L. W., Womble, D. S. & Barlow, T. A. Abundances at high redshifts: The chemical enrichment history of damped Lyman-α galaxies. Astrophys. J. Suppl. Ser. 107, 475–520 (1996).

    Article  ADS  CAS  Google Scholar 

  9. Ge, J., Bechtold, J. & Black, J. H. A new measurement of the cosmic microwave background radiation temperature at z = 1.97. Astrophys. J. 474, 67–73 (1997).

    Article  ADS  CAS  Google Scholar 

  10. Roth, K. C. & Bauer, J. M. The z = 1.6748 C I absorber toward PKS 1756+237. Astrophys. J. 515, L57–L60 (1999).

    Article  ADS  Google Scholar 

  11. D'odorico, S. et al. Performance of UVES, the echelle spectrograph for the ESO VLT and highlights of the first observations of stars and quasors. Proc. SPIE 4005, 121–130 (2000).

    Article  ADS  Google Scholar 

  12. Welty, D. E. et al. The diffuse interstellar cloud toward 23 Orionis. Astrophys. J. Suppl. Ser. 124, 465–501 (1999).

    Article  ADS  CAS  Google Scholar 

  13. Savage, B. D. & Sembach, K. R. Interstellar abundances from absorption-line observations with the Hubble space telescope. Annu. Rev. Astron. Astrophys. 34, 279–330 (1996).

    Article  ADS  CAS  Google Scholar 

  14. Pettini, M., Smith, L. J., King, D. L. & Hunstead, R. W. The metallicity of high-redshift galaxies: the abundance of zinc in 34 damped Lyman-α systems from z = 0.7 to 3.4. Astrophys. J. 486, 665–680 (1997).

    Article  ADS  CAS  Google Scholar 

  15. Ge, J. & Bechtold, J. in Highly Redshifted Radio Lines (eds Carilli, C. L., Radford, S. J. E., Menten, K. M. & Langston, G. I.) 121–131 (ASP Conf. Series Vol. 156, 1999).

    Google Scholar 

  16. Shull, J. M. et al. FUSE observations of diffuse interstellar molecular hydrogen. Astrophys. J. 538, L73–L76 (2000).

    Article  ADS  Google Scholar 

  17. Jura, M. Interstellar clouds containing optically thick H2. Astrophys. J. 197, 581–586 (1975).

    Article  ADS  CAS  Google Scholar 

  18. Dalgarno, A. & Wright, E. L. Infrared emissivities of H2 and HD. Astrophys. J. 174, L49–L51 (1972).

    Article  ADS  CAS  Google Scholar 

  19. Srianand, R. & Petitjean, P. Molecules in the zabs = 2.8112 damped system toward PKS 0528-250. Astron. Astrophys. 335, 33–40 (1998).

    ADS  CAS  Google Scholar 

  20. Bahcall, J. N. & Wolf, R. A. Fine-structure transitions. Astrophys. J. 152, 701–729 (1968).

    Article  ADS  CAS  Google Scholar 

  21. Timmes, F. X., Lauroesch, J. J. & Truran, J. W. Abundance histories of QSO absorption systems. Astrophys. J. 518, 468–476 (1995).

    Article  ADS  Google Scholar 

  22. Nussbaumer, H. & Rusca, C. Forbidden transitions in the C I sequence. Astron. Astrophys. 72, 129–133 (1979).

    ADS  CAS  Google Scholar 

  23. Launay, J. M. & Roueff, E. Fine structure excitation of carbon and oxygen by atomic hydrogen impact. Astron. Astrophys. 56, 289–292 (1977).

    ADS  CAS  Google Scholar 

  24. Jenkins, E. B. & Shaya, E. J. A survey of interstellar C I insight on carbon abundances UV grain albedoes, and pressures in the interstellar medium. Astrophys. J. 231, 55–72 (1979).

    Article  ADS  CAS  Google Scholar 

  25. Keenan, F. P., Lennon, D. J., Johnson, C. T. & Kingston, A. E. Fine structure population for the 2P ground states of C II. Mon. Not. R. Astron. Soc. 220, 571–576 (1986).

    Article  ADS  CAS  Google Scholar 

  26. Roth, K. C. & Meyer, D. M. Cyanogen excitation in diffuse interstellar cloud. Astrophys. J. 441, 129–143 (1995).

    Article  ADS  CAS  Google Scholar 

  27. Sunyaev, R. A. & Zeldovich, Ya. B. The velocity of clusters of galaxies relative to the microwave background—The possibility of its measurement. Mon. Not. R. Astron. Soc. 190, 413–420 (1980).

    Article  ADS  Google Scholar 

  28. Morton, D. C. Atomic data for resonance absorption lines. I—Wavelengths longward of the Lyman limit. Astrophys. J. Suppl. Ser. 77, 119–202 (1991).

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

The observations presented here have been obtained using the Ultra-violet and Visible Echelle Spectrograph mounted on the 8.2-m KUEYEN telescope operated by the European Southern Observatory at Paranal, Chile. P.P. thanks A. Kaufer and M. Chadid for their kind and efficient assistance at the telescope and IUCAA for hospitality during the time this work was being done. We thank T. Padmanabhan for useful comments. We gratefully acknowledge support from the Indo-French Centre for the Promotion of Advanced Research (Centre Franco-Indien pour la Promotion de la Recherche Avancée).

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Authors and Affiliations

  1. IUCAA, Post Bag 4, Ganeshkhind, 411 007, Pune, India

    R. Srianand

  2. Institut d'Astrophysique de Paris–CNRS, 98bis Boulevard Arago, Paris, F-75014, France

    P. Petitjean

  3. CNRS 173–DAEC, Observatoire de Paris-Meudon, Meudon Cedex, F-92195, France

    P. Petitjean

  4. European Southern Observatory, Karl Schwarzschild Strasse 2, Garching bei München, D-85748, Germany

    C. Ledoux

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  3. C. Ledoux
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Srianand, R., Petitjean, P. & Ledoux, C. The cosmic microwave background radiation temperature at a redshift of 2.34. Nature 408, 931–935 (2000). https://doi.org/10.1038/35050020

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