Re: Bias of our low-extinction method

From: Robert A. Knop Jr. (robert.a.knop@vanderbilt.edu)
Date: Fri May 23 2003 - 10:03:19 PDT

  • Next message: Greg Aldering: "Re: Bias of our low-extinction method"

    On Fri, May 23, 2003 at 10:00:03AM -0700, Greg Aldering wrote:
    > Note that the lack of redshift simulation could have other effects in my
    > simulation in the sense that our error bars may be systematically smaller
    > at low redshift than at high redshift. If so, the noisier high-redshift
    > error bars might be letting in extincted SNe which are in fact never
    > allowed into our sample due to the flux limit.

    This is definitely the case-- as you noted for the HST supernovae, and I
    think it is the case for P99 SNe.

    There's also the fact that at different redshifts, changes in supernova
    brightnesses push the confidence intervals in different directions. The
    0.01 mag <-> 0.01 in Omega_M applies, I believe, at around z=0.5.

    > To investigate further, we would have to couple our selection criteria to
    > a more complete extinction/flux-limit simulation, like those that Gene has
    > done. This should be possible, but could take a little time.

    Doing the flux limits right would also be hard for the same reasons that
    you wrote about the true Malmquist correction being hard.

    -Rob

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


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