From: Gerson Goldhaber (g_goldhaber@lbl.gov)
Date: Thu Aug 01 2002 - 13:21:07 PDT
Dear Mark and Richard,
I realize that your paper is out in preprint form, but I had the
occasion to study the 8 SNe from Riess you are using in the paper.
Enclosed is a result of my study. Whether you want to use any of it at
this late date is up to you.
cheers Gerson
I have fitted the 8 Riess SNe that Mark Sullivan & Richard Ellis are
using in the galaxy identification paper.
A general comment is that none of the fits are very good. Some have
chisq/DoF as high as 10.
The fits are:
1. B-fit with vertical offset free.
2. B-fit with vertical offset fixed, =0
3. B and V simultaneous fits with stretch ratio V/B = 1. offsets free
4. B and V " " " " " V/B = 1.08 offsets fixed, = 0
name 1 2 3 4
mag stret mag stret mag stret mag stret
> 1994M 16.46 0.809 16.50 0.766 16.36 0.884 16.46 0.770
> 1994S 14.89 1.018 14.93 1.005 14.92 1.132 14.89 1.054
> 1995ac 17.28 1.051 17.31 0.984 17.26 1.071 17.23 0.957
> 1995ak 16.16 0.870 16.29 0.789 16.18 0.923 16.26 0.803
> 1995bd 17.44 1.091 17.46 1.200 17.41 1.059 17.38 1.080
> 1996bl 17.13 0.938 17.05 0.991 16.85 1.005 17.05 0.936
> 1996C 16.90 0.968 16.75 1.086 -- 16.71 1.028
> 1996bv 15.96 0.949 15.77 1.087 15.81 1.053 15.82 1.016
NOTE: All magnitudes are k-corrected but NOT corrected for any
extinction nor corrected for stretch.
One possibility is to take the average magnitude and correct for the
average stretch.One can then use the Phillips 99 extinction (including
host galaxy and our galaxy extinction).Once extinction is included one
can use our stretch correction formula alpha*(s-1) with alpha=1.71.
Alternatively without host galaxy extinction but with Finkbeiner et al
extinction, alpha=0.61, as was done in our 42 SNe paper .
Gerson
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