From: Serena Nobili (serena@physto.se)
Date: Sun Jan 04 2004 - 01:25:41 PST
Dear Isobel,
thank you for you comments and your support. I will make all the changes
you suggested as soon as possible. A few relevant answers to your comments
are below.
Happy new year!
Serena
On Sat, 3 Jan 2004, Isobel Hook wrote:
>Intro:
>
>I see that there is a new paper on very low-z I-band light curves by
>Krisciunas, Philipps and Suntzeff (astro-ph/0312626) which you could
>mention.
>
I have seen this paper, however, it is not in I-band, but in JHK-bands.
I think I should still mention it, as they show Hubble diagram in the
infrared.
>Section 2:
>
>
>I dont really understand why the Ca IR triplet should cause problems
>at any z provided the filters are a good match to whatever rest-frame
>band you're aiming for. I think that paragraph needs explanation or
>remove it.
>
This is an old issue. Peter has made some noise about this problem (see
also Nugent, Kim & Perlmutter, astro-ph/0205351) and Chris has been
bugging me about the fact that my analysis, and any analysis in restframe
I band, was affected by the Ca IR triplet, which would make the
k-corrections wrong. As you said provided a good match between the filters
this is not a problem, but the good match depends on the redshift. There
are some relevant plots I put in the paper web page:
http://www.physto.se/~snova/internal/papers/iband/#CaII
I think it is fair to point it out that we don't suffer from
this problem.
>
>Section 4.4: I'm not quite sure I understand what you've done in order
>to make a set of templates which you then use for a one-parameter fit
>to the z~0.5 SNe. How did you collapse the 42 lower z ones down to one
>parameter? Are you using the curves in Figs 7 and 8?
>
>
I am simply using each of the 42 lightcurve showed in figs 1 - 5 as
template to fit the peak value (one parameter) of the high-z SNe data.
Thus I choose the template whose fit gives the lower chisq value as the
best-fit template.
>Section 5:
>
>You quote confidence levels with & without systematic
>uncertainties being accounted for, but you dont say what these
>uncertainties are. Are these the same as mentioned in section 6.1?
No, they are explained in section 4.4 and reported in table 8.
>
>In the conclusions you mention that a non-dust model is preferred at
>90% confidence but I could not see this result mentioned in section 5,
>where I would expect it to come from.
>
Yes, you are right, it is not explicitly said in Section 5, where table 9
reports the chisq value to each of the models. I will add a line in
the text of section 5.
>Section 6:
>
>To be honest I found this section a bit frustrating - there is a lot
>of quite detailed analysis to understand, and at the end of it all
>we're told there were no significant conclusions. If possible I would
>try to shorten this section.
>
I found even more frustrating to work on this for almost 2 years and get
to the conclusion that I cannot conclude anything due to poor high-z data.
However, the idea is to show a method that could be used once the data are
available. That is why it is so detailed.
----------------------------------------------------------------------
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