Re: E(B-V) vs stretch

From: Robert A. Knop Jr. (robert.a.knop@vanderbilt.edu)
Date: Fri May 16 2003 - 13:26:19 PDT

  • Next message: Greg Aldering: "Re: E(B-V) vs stretch"

    On Fri, May 16, 2003 at 01:20:04PM -0700, Greg Aldering wrote:

    > Ok, grabbed b-v_snelist.lis from your webpage, and plotted the
    > residuals (which I assumed were in the last column) vs stretch for SNe
    > within 3 stretch-corrected days of max. What I see is that the
    > residuals of the ridgeline of points misses zero by about 0.02-0.03 mag.
    > There may be some higher-order effect as well, but that is harder
    > to say with confidence.

    Last column is E(B-V), yes.

    What do you mean when you say the residual of the ridgeline of points is
    missing? What is the diagnostic that you're using?

    Of the HST SNe in the paper, when the reddest ones are thrown out (92ag
    and 93ag), the vairance weighted mean E(B-V) (based now on lightcurve
    fits) comes out at -0.004+-0.004. If the line moves any to the redder,
    we will have the "too blue Hamuy" supernovae problem again.

    I've attached a plot of E(B-V) vs. s. Again, these E(B-V) are the
    results of the snminuit fits, and thus not exactly the same thing as the
    numbers from b-v_snelist.lis (which is the E(B-V) value at the given day
    from the color curve, not from any sort of lightcurve). The ellipticals
    (the ones from the list you sent me) are the black points. This
    distribution looks pretty good to me.

    -Rob

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




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