Re: further thougths on CMB vs. Helio redshifts

From: Robert A. Knop Jr. (robert.a.knop@vanderbilt.edu)
Date: Wed Apr 16 2003 - 09:29:17 PDT

  • Next message: Michael Wood-Vasey: "Re: further thougths on CMB vs. Helio redshifts"

    On Wed, Apr 16, 2003 at 09:25:39AM -0700, Michael Wood-Vasey wrote:
    > BTW, when doing this it's a lot easier to start from the beginning and
    > figure out the z from spectra shifted to the CMB frame rather than
    > apply a correction later. It's the discussion of how to correct
    > already-derived redshifts that makes things confusing.

    Not just spectra -- you also have to correct the luminosity distance,
    which is observed in our (geocentric) frame. I was trying to correct
    that by just using a different redshift. Instead, should I figure out a
    Lorentz transformation from the Helio frame to the CMB frame to fix the
    flux, and just use CMB redshifts? That would probably be the right
    thing to do.

    Instead, I'm tempted to "just use CMB redshifts" and not mention it,
    because we know nobody will notice (they never have in the past), and
    because we know that these details make no difference except for a
    slight change in alpha and a slight change in the chisquare.

    -Rob

    -- 
    --Prof. Robert Knop
      Department of Physics & Astronomy, Vanderbilt University
      robert.a.knop@vanderbilt.edu
    


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