Re: K-corrections: another voice in the debate

From: Peter Nugent (nugent@lbl.gov)
Date: Wed Mar 10 2004 - 05:46:21 PST

  • Next message: Alex Conley: "Re: K-corrections: another voice in the debate"

    > When Peter did it, I believe he did it as a function of t rather than
    > t/(1-s). Is this right Peter?
    >
    > My belief is that the differences will be smaller if you do
    > K-corrections as t/(1-s) rather than as t. (I think Serena came to the
    > same conclusion.)

    I did it both ways, but t/(1+s) had smaller dispersion (I think we have
    the plus sign there)

    > As such, the 0.2 may be larger than even the "biggest reasonable case"
    > systematic uncertainty.

    This 0.2 was only for I-to-I corrections where the CaII IR triplet
    dominates the entire bandpass. I have found 3 SNe (out of perhaps 20) that
    have problems on this magnitude. In general it is much less (<< 0.05). It
    is the fact that one feature dominates the bandpass that can cause havoc
    and the fact that the number of observations out there is limited so I
    don't know how to address the problem well.

    Cheers,

    Peter

    __
    Peter E. Nugent
    Staff Computational Scientist - Scientific Computing Group - NERSC
    Lawrence Berkeley National Laboratory
    M.S. 50F-1650 - 1 Cyclotron Road - Berkeley, CA, 94720-8139
    Phone:(510) 486-6942 - Fax:(510) 486-5812
    E-mail: penugent@LBL.gov - Web: http://supernova.LBL.gov/~nugent

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