From: Gabriele Garavini (garavini@in2p3.fr)
Date: Tue Dec 14 2004 - 03:43:19 PST
Dear All,
I've implemented the changes Chris suggested. Please find the new version
of the paper in the usual Stockholm web page:
http://www.physto.se/~snova/private/internal.html
I remind everybody that the paper should be discussed in the exec phone
conference of December the 21th.
Please find detailed answer to the points raised in what follow.
Thank you very much.
Cheers
Gabriele
> Introduction
> ============
>
> The first paragraph could still be improved. The first (and last)
> paragraphs in a paper are important, so it is worth spending time
> getting them right. I don't have any specific suggestions but you
> might want to think of the following.
>
> Before launching into the assumptions we make about low and high
> redshift SNe, perhaps you can start differently.
>
> - First, mention that the accelerating universe and dark energy were
> discovered through high-z SNe (with all the standard references),
>
> - then mention that there are now even more ambitious programs that aim
> to try to constrain the nature of the dark energy and that a good
> control of the systemmatic errors in these new surveys is critical
> to their success
======> I've added two phort paragraphs at the beginning of the
introduction
> ----
>
> In paragraph 3, change
>
> "As of now few attempts have been made to quantitatively compare
> supernovae properties at different redshifts and only based on light
> curve parameters ..."
>
> to
>
> "However, the number of studies that quantitativrly compare the
> obsereved propoerties low and high redshift SNe~Ia are still very few
> ..."
>
> and then add a reference to Isobel's work as she makes a comparison
> between
> the CaII velocities oif low and high z SNe as you do in figure 4.
>
> ----
>
> Add a reference to Isobel's work in paragraph 5.
>
> ----
>
> Remove the double quote at the end of the last paragraph.
=========> I've made the changes as you suggested.
> Section 2.1
> ===========
>
> In the first paragraoh, replace
>
> "Since SN2001go was observed at three epochs, there ..."
>
> with
>
> One SNe, SN 2001go, was observed at three epochs, so there ..."
>
> In the second paragraph, drop the clause "and scaled to the width in the
> trace of the supernova.
>
> In the fourth paragraph, refer to Isobel's paper when quoting the
> accuracy of the dating with spectroscopy.
=========> I've made the changes as you suggested.
> Figure 1
> ========
>
> Have a look at how Isobel has done figure 18 in her paper. This figure
> in
> Isobel's paper looks really nice and is very informative.
========> I think that Isobel's figure is nice but I think you arleady
showed the comparison with the low-z SNe in your paper I just
need to show the data I use for the analysis.
> Figure 2
> ========
>
> The lower axis has only one number.
=======> Thanks to note that
> Section 2.4
> ===========
>
> I think that this section and the figure can be removed. It does not
> add much to the paper. However, you can leave it in for others to see
> and
> you can wait until you have had comments by others before deciding if it
> should go.
==========> I agree. We should remove this section. Let's see what the
rest of us think.
> Figure 4
> ========
>
> You might think about adding Isobel's points to this diagram.
=======> I would prefer to keep the data sets separated for
the moment since there will also be a EW paper on those data.
> Section 4
> =========
>
> I think that you should remove the last paragraph.
>
============> Thanks I've removed it
>
> On Wed, 2004-12-08 at 09:03, Gabriele Garavini wrote:
> > Dear Tony, Dear All,
> >
> > I think we can discuss the Evolution paper on the 21th.
> > You now find the latest version in the usual link in the Stockholm
> > web page : http://www.physto.se/~snova/private/internal.html
> >
> > Since is not known to everybody I'm going to briefly resume the discussion
> > Eric, Rob and myself had on the possible systematics related with the
> > measurements of the EW on high redshift SNe. The bottom line was that Eric
> > was finding a systematic difference in between the measurements of EW he
> > was doing on the 97 SCP dataset (I believe) and those Gaston did (and
> > that I report in my paper) on the VLT data presented in Chris's paper.
> >
> > The issue was solved (at least that's the way I understood it) saying that
> > Gaston did not rebin the data for finding the maxima around the features,
> > while Eric did. The problem is of course related with the S/N ratio of the
> > measured spectra and the ability to recognize the features.
> > This is why these measurements should be done on decently
> > high signal to noise SNe spectra.
> >
> > There is also an other possible source of systematics
> > in the amount of galaxy removed and the technique used to do
> > that. We did not use the same techniques (I used Gregory's code, Eric used
> > Andy's) and Me and Gaston estimated (based on a work that Gregory Sainton
> > did ) that a possible uncertainty of 10% should be allowed in this
> > process. The effect of this uncertainties on the EW was added in
> > quadrature to the EW measurements errors.
> >
> > I find peculiar that Eric was reporting a systematic difference only in
> > the measurements of EW of MgII but not in FeII. This might be more due to
> > the galaxy subtraction than to the way the EW was measured. I personally
> > believe there is not much of a difference between Gaston's method and
> > Eric's method if one takes into account the error bars and the identified
> > systematics.
> >
> > Cheers
> >
> > Gabriele
> >
>
>
>
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