From: Chris Lidman (clidman@eso.org)
Date: Wed Oct 20 2004 - 15:24:35 PDT
Hi Serena,
Many thanks for the very quick reply. Here is some follow-up.
> > Section 4.3
> > -----------
> >
> > 2nd paragraph
> >
> >
> > I think you should delete the last sentence concerning the IR
> > photometry in this paragraph. Although I have re-reduced the data,
> > I'd like someone to check my estimate of the magnidude independently.
> >
>
> Is someone checking it? I think it is important to say that we have
> doubts about their IR data, otherwise I don't see the whole point of
> excluding this SN from the analysis. The doubts on the optical lightcurves
> are not enough since there should be more ground based data that we don't
> have (at least according to Riess' paper).
>
I'll ask Ramon to check my IR photometry estimate.
>
> > 3rd paragraph
> >
> > According to http://panisse.lbl.gov/collab/archive/iband/0056.html
> > the time of B-max in case 3 is 51190.4 +/- 1.5 days, which is only
> > 4 observer frame days before the Tonry value and not 8 days which is
> > based on the HST data alone. I think that you should change the 8 to 4.
> >
>
> The latest fit by Vitaliy is:
>
> http://panisse.lbl.gov/collab/archive/iband/0150.html
>
>
Thanks for the plot.
This plot makes me nervous as there is no data before
maximum light. Hence, I do not think that the estimated
errors in the stretch and the date of maximum light are
particularly reliable.
Hence, I think that you were correct in using the Tonry date as they
have presumably done the fit to data that includes points that
were taken before maximum light. At the same time, I do not think we
should mention that we find a different date for the maximum as we
are probably using an inferior data set.
I would suggest that you replace section 4.3 with something like the
following
SN 1999Q was discovered by the HZSST using the CTIO 4m Blanco
Telescope and was spectrally confirmed to be a Type Ia SN at $z=0.46$
(Garnavich et al. 1999). The reddening due to our galaxy is E(B-V) =
0.021 magnitudes (Schledel et al. 1998).
SN 1999Q was observed in the J band over five epochs, the first
with SofI on the ESO NTT and the following four with NIRC at Keck
Telscope (Riess et al. 2000). We recomputed the k-corrections using
our new spectral template (as we did for SNe 2000fr and 1999ff) and
we find a disagreement of up to 0.15 magnitudes between our
k-corrections
and those published in Riess et al. (2000). The rest frame I-band
magnitudes, obtained with our k-corrections, are reported in Table 7.
The restframe B- and V-band data on SN 1999Q have not yet been fully
published;
however, the HST data is publicly available, and together with the
discovery point reported in the IAU circular (Garnavich et al. 1999),
we have fitted the lightcurve and computed the B-band stretch, which
we find to be $s=1.10 +/ 0.03$. Since these data do not
adequately cover the rising part of the lightcurve, we force the date
of maximum to occur at 51194.65 (Tonry, private communication) and we
note that there may be a significant systematic error in the fitted
stretch.
The restframe B-V colour is considerably redder than the average SN Ia
with $s=1.1$ (see figure 13), which might mean that SN 1999Q is
significantly reddened or that the stretch has been overestimated. In
contrast, the B-I colour is quite normal for a SN Ia with $s=1.1$ (see
figure 13). As we will show in the sections that follow, SN 1999Q is
also unusually faint in the rest frame I-band. This makes SN 1999Q
an interesting object.
For these reasons, we fit a lightcurve to the rest frame I-band data
of SN 1999Q and we include it in all the plots that follow; however, we
do
not include it in our analyses. We will defer this to the time when
all the data, including the spectrum and the ground based optical
photometry, have been published.
> > 2nd paragraph
> >
> > I have a question about the B-I colours of 99Q. Do we use the B-band
> > magnitudes of Riess et al., or do we redetermine them from the HST data
> > that was retrieved from the archive using our own light curve fitting
> > software and our own k-corrections?
> >
> >
>
> We use the B-band magnitudes of Riess et al for consistency reasons, since
> we are also using the time of Bmax by them. As I said, I don't like using
> our optical lightcurve fit, since there could be more data.
>
How do our B-magnitudes compare to theirs?
>
> > Section 7
> > ---------
> >
> > 2nd paragraph
> >
> > "colors" -> "the colours" (note the English spelling)
>
> I believe I used the American spelling throughout the paper
> (e.g. gray instead of grey). But maybe I have not been consistent. If so,
> please let me know.
>
>
I think A&A requires British spelling (and grammar) :)
Chris.
>
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