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16.4 GHz radio sources

  1. Aug 22, 2014 #1

    Just wondering if 16.4 GHz (or so) is a commonly encountered frequency in radio astronomy ? Because I'm theorising a possible secondary photon emission following photon emission and electron recoil in the Hydrogen 1s - 2s transition.
  2. jcsd
  3. Aug 22, 2014 #2


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    Yes, 16.4 GHz is indeed commonly encountered in radio astronomy. Let us know here at Physics Forums if you get satisfaction. Post your questions here and you may expect highly qualified and experienced members to help guide you along your search.

    Here are two papers that seem to be about your subject:

    Swift satellite catches a hundred thousand new cosmic X-ray sources
    Dec 16, 2013


    Unexpected source of gamma rays discovered
    Mar 06, 2009

    Cheers, Bobbywhy
  4. Aug 22, 2014 #3


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    Where abouts Bobbywhy ?

    I cannot find any references in google
    including those 2 links you gave

  5. Aug 23, 2014 #4
    Well I guess I should rephrase the question as "is 16.4 GHz a commonly encountered peak frequency in radio astronomy". Since the cosmos produces - it would seem - just about every frequency there is! I also tried to google "16.4 GHz" and "16.4 Gigahertz" but not much seemed to come up.
  6. Aug 23, 2014 #5


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    OOPS! So sorry, I carelessly and mistakenly posted some GHz references. Thanks davenn for watching out for the integrity of our Forum’s posts!

    There are astrophysical sources of this microwave 16.4 GHz frequency. Many new and planned radio telescopes are being built now will monitor it. Two sources are Galaxy ESO 149-3 and the Hubble image shows NGC 1566. A few other examples are:

    Mon. Not. R. Astron. Soc. 386, 1729–1738 (2008) doi:10.1111/j.1365-2966.2008.13161.x
    Multifrequency spectral analysis of extragalactic radio sources in the 33-GHz VSA catalogue: sources with flattening and upturn spectrum

    arXiv.org > astro-ph > arXiv:astro-ph/0102497v1



    AMIGPS16GH - AMI Galactic Plane Survey 16-GHz Source Catalog

    Perrott, Y. C., A. M. Scaife, N. Hurley-Walker, and K. J. Grainge. 2013. “Investigating the Source of Planck-Detected AME: High-Resolution Observations at 15GHz.” Advances in Astronomy 2013: 1-9.

    Perrott, Y. C., A. M. Scaife, D. A. Green, M. L. Davies, T. M. Franzen, K. J. Grainge, M. P. Hobson, N. Hurley-Walker, A. N. Lasenby, M. Olamaie et al. 2013. “AMI Galactic Plane Survey at 16 GHz – I. Observing, mapping and source extraction.” Monthly Notices of the Royal Astronomical Society 429: 3330-3340.
  7. Aug 23, 2014 #6


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    neilparker62, Just a comment from me: Whether or not that frequency is common or not, your underlying proposal may have merit.

    There may be an undiscovered photon emission mechanism. It takes persons like you to form the hypothesis, and then try to disprove it...

    I congratulate you for your searching for this transition; who knows, in future it could be known as the "parker trasnsition". Keep on searching.

    Cheers, Bobbywhy
  8. Aug 24, 2014 #7
    Many thanks Bobbywhy for your kind words - I am indeed greatly encouraged! Perhaps I'm pushing my luck a bit here but can I request someone with one of those frequency comb thingies (please excuse the rather ignorant sounding description!) to please very carefully check the Hydrogen 1s 2s emission and absorption line frequencies (separately if that's possible) and see if perchance there is not a 16.4GHz difference. Also check for 16.4 GHz 'rebound' emission. If that is found, then perhaps I need to submit a paper on whence is determined 16.4GHz.
  9. Aug 24, 2014 #8


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    Here please find three possibilities you may find a real radio astronomer to deal with your questions:


    Do you have a burning question you'd like to ask an astronomer? Feel free to email it to us (education@icrar.org) and we'll get you an answer.

    National Radio Astronomy Observatory, Ask a Radio astronomer at https://blogs.nrao.edu/askanastronomer/
  10. Aug 25, 2014 #9
    Here's an article I found which has a very specific reference to a 'mean frequency' of 16.4GHz. But the article was way too technical for me to understand - don't know if it would be significant in respect of this thread ?

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