From: Andy Howell (DAHowell@lbl.gov)
Date: Thu Mar 13 2003 - 18:25:53 PST
Rob,
Thanks for addressing my previous comments. I especially like the web
page which answers just about any question one could ask. Having said
that, here are a few more things!
Template issue:
Forgive me for only noticing this now, but your template on p. 9 has the
V reaching maximum at
day 1 relative to Bmax. While there is a large distribution in
differences between day of Vmax and Bmax,
it is more typical for there to be a two day delay. For R there may be
an even bigger difference, but you also have only a 1 day delay. Since
you are doing simultaneous fits, if you are systematically off by a day,
I would expect this to lead to a systematic error in stretch (at least)
that could bias the results. Gerson's V template peaks at day = 2.
SN typing issues:
-p. 4 "All eleven supernovae in the set have strong confirmation as type
Ia, although there is no confirmation of the SiII feature for the three
highest redshift supernovae."
This is wrong in two ways that almost cancel out. First, we can in
principle measure the weaker Si II ~4000 A line for all of them. Plus
we can measures the SII lines at 5300 and 5500 A (get the exact
wavelengths from Peter, who has the atomic line data) for some of them.
We do see at least one of these indicators for all of them except maybe
98104 (98ay), 97201 (97ek). Si II may be there in 97201, but it is hard
to say. For these two, the spectra are still consistent with them being
a Type Ia, but I wouldn't exactly call it "strong confirmation" (i.e.
there is nothing bulletproof).
-p.15-16 Thank you for doing the fits with uncertain SNe omitted. I saw
the difference on the web between
the Subset 1 and "definite Ia's (subset 3). (It makes a 0.01 difference
in Omega_m). Question 1: Are subsets 3 and 4 plotted anywhere in the
paper? If not, there is no need to refer to them. Question 2: Is the
difference in Omega_m=0.25 -> 0.22 using only the P99 SNe from the last
draft to the present draft due to the removal of the five suspect SNe?
If so, this is big and should be mentioned.
SN redshift issues:
I see that SN 1998bi (98142) is listed as z=0.740.
This spectrum:
http://panisse.lbl.gov/collab/data/spec/homesp/keck_mar98/reduc_tel/98142_snz.ps
Says z=0.748, though Isobel's notes say that there are "no clear galaxy
lines, possibly OII."
Most references to it are z=0.75, including IAUC 6881.
Wording issues:
Kudos for the partial unmangling of the English language.
However, there are still some issues, such as redundant words or phrases
-p. 11 "this present paper" present is redundant
-p.14 the whole phrase "so as to measure an intrinsic U-B color that is
likely to be right" is redundant.
-p. 15 "parameters resulting from" resulting is redundant
-p. 16 "K-corrections resulting from": resulting is redundant
-p. 17 "can potentially introduce a bias": potentially is redundant
-p. 20 "Figure 4 shows Hubble Diagrams which plot": "which plot" is
redundant
-p. 20 "resulting uncertainty on mB": resulting redundant
-p. 27 (Fig. 7) "resulting from": resulting redundant
-Amost every time you say "quoted" it is redundant.
Other nitpicks:
-Abstract: Last sentence is 6 lines long! Split into two.
-Calling the unknown stuff a cosmological constant presumes you know
what it is.
-p. 2 "Yield" used twice in the first two paragraphs -- use a different word
-Wide Field/Planetary Camera -> Wide Field Planetary Camera 2 (no slash,
add the 2).
-p. 3 when talking about dust should we mention that it is normal dust
and not gray dust?
-p. 6 Fruchter (2000) -> (Fruchter 2000)
-p. 8 "fit to template" needs an article
-p. 11 "date of H96" -> data of H96
-p. 15 "Which supernoave are omitted from which subsets" -> the
supernovae omitted from each subset
-p. 15 "Because we have greater statistics than the previous SCP quoted
in P99" -> because we have better statistics than P99
-"Six additional supernova" -> supernoave
-p. 17 "their included zero weight" -> "they included..."
-"shows treats the H96" -> treats
-"a s=1" -> an s=1
- "a SN Ia" -> an SN Ia
-p. 22 "of the Milky Way extinction correct" -> correction
p. 25 "a prior" -> a priori
p. 29 "a ~ 80%" -> an
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