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Globular cluster luminosity function

  1. Apr 22, 2015 #1
    So I was interested in how astronomers measure the distances to other stars, galaxies, etc and I found this pdf about the subject http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1992PASP..104..599J&data_type=PDF_HIGH&whole_paper=YES&type=PRINTER&filetype=.pdf [Broken]
    It seems to be a good source but I still don't understand exactly how it is done, and don't have a high level of math understanding yet. I'm mostly interested in the globular cluster luminosity function, and the steps taken to actually get a distance to another galaxy etc. I understand a little bit about it but there is quite a bit such as the math that I don't understand. Can anyone help and explain this to someone who doesn't know much about the subject? Thank you.
     
    Last edited by a moderator: May 7, 2017
  2. jcsd
  3. Apr 23, 2015 #2
     
    Last edited by a moderator: May 7, 2017
  4. Apr 27, 2015 #3
    Thank you for the response though there wasn't much about GCLF it was helpful
     
  5. Apr 28, 2015 #4
    The Globular Cluster Luminosity Function is based upon the premise that old (metal-poor) globular clusters exhibit a universal shape in luminosity that can be characterized by some number that can be used as a "standard candle." However, the systematic error inherent in the GCLF method makes it less accurate than measuring Surface Brightness Fluctuations, Planetary Nebula Luminosity Function, or classical Cepheid variable distance indicators. It has also been suggested that super-Chandrasekhar Type 1a SNe are more likely in globular clusters due to the integrated flux density of pulsars. The use of the GCLF to determine cosmological distances hinges on accurate and relevant calibration of the zero-point of the GCLF turnover and shape.

    Sources:
    Globular cluster luminosity function as distance indicator - Astrophysics & Space Science (September 2012), Volume 341, Issue 1, pp 195-206 (paid subscription) - arXiv free reprint
    Dynamical friction in constant density cores: a failure of the Chandrasekhar formula - Monthly Notices of the Royal Astronomical Society (2006) 373 (4): 1451-1460, published December 21, 2006 (free issue)
     
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