Window to the Very Early Universe and some problems of “ μK Astrophysics”

  • Yu. N. Parijskij
Conference paper
Part of the NATO Science Series book series (NAII, volume 130)


A few years ago it was demonstrated by several groups that we can see predicted by theory small scale CMB anisotropy at the recombination epoch, z = 1000. It means, that:
  1. 1.

    We can check the history of evolution of the primordial disturbancies up to the recombination time.

  2. 2.

    There was an extended epoch of “neutral” Universe when gravitation formed proto-objects from very small relative disturbancies, say, 10•5, up to more than 105 (”DARK AGE”, 10 < z < 1000).

  3. 3.

    The size of the “Luminous Universe” is limited by some redshift, say, z = 10.


There are many projects connected with item 1 (PLANCK mission - the most ambitious one), and with item 3, (NGST - the most ambitious in optics from Space, and 100m — 5000m in diameter - the most ambitious ground-based optical- IR telescopes, SKA - in Radio).

The situation with facilities for the ”DARK AGE” Universe is not so clear [1], and we shall discuss here this item. Neutral epoch of the Universe cannot be observed by optical tools because of strong absorption beyond Layman limit, and radio tools are the first and may be the only possibility. As in the early history of Radio (first half of the 20th century), when there where many researches connected with propagation effects in the Earth atmosphere before optimal band for the “people-to-people” communication was found, at the end of the last century hundreds of papers appeared in attempts to find the best widow to the Early Universe and “DARK AGE” of its history (“people-to-Big Bang” window). Here we present a recent data, collected by different groups, including new data from RATAN-600 multi-frequency focal field array [2]. New data on the “polarization noise” from the Galaxy will be discussed, and a large difference with predicted values from lower frequencies and greater scales will be explained by “Faraday cleaning” process. A new upper limit on the “spinning dust” emission, more stringent, than before, simplifies the situation in the low frequency part of the Galaxy window [3].

Most groups agree that in the frequency domain the best window is in the 1cm – 1mm region. In the angular scale domain (or on the “l-axis”) the lower l is limited by “recombination noise” by l=3000, above which “Silk Damping” process acts strongly. High l boundary for small telescopes is instrument-depending and was computed individually for all projects.

Appearance of the “Redshift cutoff” effect suggests that there are no instrumental boundary now, if the number of antenna beams on the sky is greater than the number of galaxies in the Universe. Even existing instruments are close to this situation (e.g. VLA at short wavelengths).

In this paper we estimate how deep the window on the frequency-scale plane is and how close we can be to the expected secondary anisotropy effects suggested in literature (e.g., [4, 5, 6]).

We show that there is small window to the “DARK AGE” epoch where experiments with sensitivity below 1 μK in brightness temperature are possible if adequate instrumentation will be invented. One way of the solution connected with very big receivers focal array in big reflectors will be discussed in much more detail. Present day status of this direction at RATAN-600, the biggest reflector type instrument, will be shown. A possible role of the next generation bolometers in Space [7] will be mentioned as well.


Brightness Temperature Cosmic Microwave Background Radio Source Early Universe Receiver Array 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [1]
    Y. Parijskij (2001) The High Redshift Radio Universe, in N.G. Sanchez (ed.), Current Topics in Astro fundamental Physics: The Cosmic Microwave Background, Kluwer Academic Publishers, Netherlands, 219–239.CrossRefGoogle Scholar
  2. [2]
    A.B. Berlin, G.M. Timopheeva, N.A. Nizhelsky, A.V. Bogdantsov, A.M. Pillipenko, V.M. Chmil, Yu.N. Meshkov and A.N. Zdor (2000) MARS (Matrix Radiometric System) Project, Astronomical and Astrophysical Transactions, 19(3-4), 559–565.ADSCrossRefGoogle Scholar
  3. [3]
    Yu. Parijskij, A.B. Berlin, A.V. Bogdantsov, N.N. Bursov, N.A. Nizhelskij, P. Tsibulev, I.D. Novikov, P.D. Naselskij (2002) Small Scale I,U,Q Galaxy Noise at sm.Waves, in S. Cecchini et al. (eds.), Astrophysical Polarized Backgrounds AIP, New York, 51.Google Scholar
  4. [4]
    P. Tozzi, P. Madau, A. Meiskin, M. Rees (2000) Radio Signatures of Hi at High Redshift:Mapping the End of the “Dark Ages”, Ap.J. 528, 597–606.ADSCrossRefGoogle Scholar
  5. [5]
    N.Yu. Gnedin, A. Jaffe (2001) Secondary Cosmic Microwave Background anisotropies from cosmological reionozation, Ap.J. 551, 3–14.ADSCrossRefGoogle Scholar
  6. [6]
    V. Dubrovich and B. Partridge (2000) Line and Continuum Emission from High Redshift Objects and Proto-Objects, Astr.&Astrophys. Trans., 19(3-4), 233–251.ADSGoogle Scholar
  7. [7]
    V.D. Gromov, L.S. Kuzmin, D. Chouvaev, L.A. Gorshkov, N.S. Kardashev, V.I. Slysh, S.F. Stoilo, M.A. Tarasov, A.G. Trubnikov, A.N. Vystavkin (2001) Submillimeter Telescope for the Russian Segment of the ISS: Submillimetron project, astro-ph/0108491.Google Scholar
  8. [8]
    Y.N. Parijsky, P.T sibulev (2000) Limit on the Ground based CMBA Experiments, Astro, and Astroph. Transactions, 9, issue 3-4, 287.ADSCrossRefGoogle Scholar
  9. [9]
    T. Drain, A.Lazarian (1998); Ap.J. 494, L19ADSCrossRefGoogle Scholar
  10. [10]
    G. Giardino, A. Banday, K. Gorski, K. Bennet, J. Jonas, J. Tauber (2002), Toward a model of full-sky Galactic synchrotron intensity and linear polaririsation: a reanalysis of the Parkes data, Astro-ph/0202520, subm. to A&A.Google Scholar
  11. [11]
    N.S. Soboleva, A.V. Temirova (2001) Spectral Characteristics of Faint Radio Sources of the Kholod Survey, Astron. Journal (Russian), 78, N12, 1066Google Scholar
  12. [12]
    DASI WEB-site, Sept. 19, 2002 news.
  13. [13]
    T. Pearson, B. Mason, A.C. Readhead, M. Sheherd, J. Silvers, P. Udomprasert, J. Cartwright, A. Farmer, S. Padin (2002) The Anisotropy of Microwave Background to 1=3500: Mosaik Observations with the Cosmic Microwave Imager, Astro-ph/0205339 Google Scholar
  14. [14]
    M. Tegmark, D. Eisenstein, W. Hu, A. de Oliveira-Costa (2000) Foregrounds for the Cosmic Microwaves Backgrounds, Ap. J., 530, 133ADSCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2003

Authors and Affiliations

  • Yu. N. Parijskij
    • 1
  1. 1.Special Astrophysical Observatory of the Academy of SciencesNizhnij Arkhyz, Karachay-CherkessiaRussia

Personalised recommendations