From: Chris Lidman (clidman@eso.org)
Date: Sun Mar 13 2005 - 11:44:00 PST
Hi Gabriele,
I've gone through the March 4th version of the evolution paper and I
think that it is ready for the collaboration to see for a second
time. It has been at least six months since the collaboration first
saw it and some parts have been modified since then, so I think
that they should be given the opportunity to comment on it before it
is submitted.
I understand that Rob (and Eric?) are happy with the wording,
especially in the sections that describe how EWs are measured.
I have some additional comments on the present draft that you might
like to consider before asking Tony to distribute the paper to
collaboration.
Cheers, Chris.
Abstract
========
We might want to qualify the statement about the statistical
significance of our claim that we do not detect evolution. I suggest
that you add the phrase, "With this small sample, we find no ..."
Although I suggested it some time ago, perhaps the word "pseudo" is
unnecessary, since it is not used in the paper again.
Introduction
============
The first three paragraphs of the introduction are still a bit weak.
Reynald can help you with that.
The 3rd and 4th sentences in the 5th paragraph seem to be out of place.
The 3rd sentence should really go at the beginning of the 6th paragraph
and the 4th sentence can be deleted, since the point of this
sentence is discussed in the the 6th paragraph.
Section 2.1
===========
2nd paragraph. It may be worth mentioning why the error spectrum in
important, i. e. we use it to estimate the errors in the quantities
we compute.
Last paragraph
"an light" -> "a light"
"the supernova spectral features" -> "supernova spectral features"
Figure 1.
========
Can you double check the rest frame wavelength scale. Some seem to be
wrong. SN 2000 fr is one example. The 4000 Angstrom tick mark lies
beyond the Si II line.
The date for sn01go is covered by the plot.
Table 2.
========
The columns describing the morphology of the features that are used to
sub-type Ias should be moved so that they are next to the
normal Ia column. I. e. move columns 6 and 7 next to column 3.
The comments column can be deleted and the comments can be attached to
the names of the features.
Section 3.1
===========
Garavini et al 2004 should be Garavini et al. in prep. What is this
paper by the way?
You should mention the results of Isobel's work in the 3rd paragraph.
You should not plot the results on Fig 3., since her paper has not
yet been accepted.
Section 3.2
===========
I think that the first paragraph could be worded better. Try the
following
"Folatelli (2004b) defined quantities that are similar to the equivalent
widths that are used in stellar spectroscopy. However, as they pointed
out, in the case of supernova spectra, the relationship between these
quantities and the physical conditions of the ejecta is complex.
However, this does not prevent us from using these well defined
quantities when comparing nearby and distant SN~Ia spectra. In the
rest of this paper, we will refer to these quantities as equivalent
widths (EW)."
I wanted to avoid the clause "can not be used to derive physical
information because of the lack of a real continuum to ..."
In the 3rd paragraph, replace "poor data quality" with "noisy data".
Section 3.2.1
=============
The last sentence. By using a larger fitting region to analyse high-z
SNe (I appreciate that this is necessary), you are adding a bias.
If it is possible, it might be worth to work out how big this bias is
and to replace the last sentence in this paragraph with an estimate
of how big this bias is.
Section 3.2.2
=============
"addiction" -> "addition"
Section 3.2.3
=============
The systematic error caused by shifts in the fitting region is a
possible systematic uncertainty (as you correctly point out in the
caption to section 3.2.2). Whenever you mention this uncertainty, you
should use the adjective possible. Indeed, when this
uncertainty is included, the chi-sq values in table 5 are too good.
In the 4th paragraph, change "It has to be noted ..." with "We note ..."
Move "before maximum light" before the verb "are".
Delete the word "included".
Add the following "clause" before the word "the deviation"
" ... a simple chi-sq. tests shows that ..."
Section 3.3
===========
Is it normal to propagate the uncertainty in the x-axis in this way?
Table 5
=======
"only the statistical and systematic uncertainties"
Section 4
=========
Delete the vague last sentence in the second last paragraph.
-- European Southern Observatory Alonso de Córdova 3107, Vitacura Casilla 19001, Santiago 19 CHILEPh. +56 2 463 3106 FAX +56 2 463 3001
This archive was generated by hypermail 2.1.4 : Sun Mar 13 2005 - 11:44:32 PST