Re: a note on sn1999Q

From: Serena Nobili (serena@physto.se)
Date: Sat Jan 17 2004 - 07:08:21 PST

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    Dear Vitaliy,

    this is exactly what I said about this problem: the plotted points do not
    correspond to the values reported in the table. I also wrote directly to
    Riess to ask him to clarify this, but he simply said the inconsistency was
    not very important. Now, as you pointed out, it is as large as 2 days up
    to 4 days for one of the points. I guess Riess and I have different
    opinions about what is "important". I concluded that the values in the
    table are the correct ones, also because they agree with the other figure
    (the one showing B-I vs. time). Perhaps I will have to add a footnote in
    the paper explaining this, since the reader can get confused by the
    different looks of the figure.
    Thanks for you note.
    Cheers

             Serena

    On Fri, 16 Jan 2004, Vitaliy Fadeyev wrote:

    >
    >Dear Serena,
    >
    >when we had our phone meeting on Thursday,
    >somebody noted that the lightcurve figure in Riess 2000
    >looks different from your fit of 1999Q. If I remember
    >this right, the difference in magnitudes was attributed
    >to k-corrections.
    >
    >It also appears that the rest-frame observation times
    >(relative to B maximum) reported in Table 1 and Figure 1
    >in that paper are inconsistent. I "measured" the times
    >on the plot with a ruler, this is only good to about 0.5 day.
    >However, the effect is clearly visible by eye if you look
    >at the distance between two points at about 30 days,
    >and at the position of the last point on the plot.
    >
    >Table Figure Difference
    >(column 2)
    > 6.2 5.0 1.2
    >14.5 12.0 2.5
    >30.2 26.0 4.2
    >32.9 30.0 2.9
    >45.3 43.0 2.3
    >
    >Column 1 of the Table is consistent with column 2, so
    >perhaps the table is correct, and it looks like this is
    >what you used for your analysis. But the "time perturbation"
    >may be contributing to the different appearence, especially
    >since your fit gives the 2nd maximum at about 20 days,
    >and from Riess's plot one could conclude something
    >like 30-35 days after B max.
    >
    >Cheers,
    >vitaliy
    >
    >
    >
    >

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