comments on SC3

From: Greg Aldering (aldering@panisse.lbl.gov)
Date: Tue May 20 2003 - 23:48:41 PDT

  • Next message: Ariel Goobar: "clarification"

    Hi Rob,

    Here are the rest of my comments. There are more than I thought, but I have
    partitioned them as being "Important", "Intermediate" or "Minor". Minor can
    be fixed after submission, but shouldn't be forgotten.

    - Greg

    Important:

    p 4: "... only significant for one of the eleven ..." --->
          "... only significant for three of the eleven ..." (or whatever the number is)

    p13 Table 3: update the footnotes for SN1998be if it is no longer excluded from the
                 low-extinction subsample.

    p18 : The end of the last full paragraph on the left side has to be updated to reflect
          the true numbers and names of the reddened HST SNe. Search for "three of the",
          "1998be", and "includes seven". You might want to make these defined variables
          in the LaTeX file so you don't have to hunt for them over and over again.

    The explainations in the section "Color and Extinction" really needs to
    be clarified. The only reason the P99 Fit C analysis worked -- and the
    only reason that the low-extinction subsample in the current analysis
    isn't laughable in the face of 30% reddened HST SNe --- is because we
    believe that the extinction distribution has a strong peak at very low
    extinction, as in the Hatano et al models. Further, we assume that this
    peak is strong and present at both low and high redshift. Our E(B-V)
    data seem to support this picture, but do not prove it to the necessary
    accuracy (i.e. to better than 0.01 in E(B-V)) simply because of
    measurement uncertainties. If not for the strong peak, the mean
    extinction would be strongly dependent on the chosen cut-off for the
    low-extinction sample. Since our cut-offs are subject to measurement
    error, the mean would even be biased between low- and high-redshift
    because the true cut-off would vary from SN to SN if the peak were not
    there to "stablize" the mean. (Imagine a flat extinction PDF - the
    mean would really depend on setting the red cut-off the same at all
    redshifts.) The difference between this assumption and that of Riess is
    that we are not as dependent on the functional form of the extinction
    PDF (although without the peak we might be just as dependent) and we
    don't use an assumed knowledge of the PDF to modify data points and
    their error bars. So, to be consistent and honest in this discussion
    throughout the paper, we have to embrace the idea that the extinction
    PDF in nature is reasonably like that calculated by Hatano et al, while
    rejecting use of the extinction PDF as a Bayesian prior. How to say
    this an not cause panic and mayhem?!

    p19 : Again, "Four of the eleven" and "three of these" need to be updated.
          Also, the end of the first full paragraph on the left, and the beginning
          of the following paragraph have a lot of overlap which should be
          streamlined.

    p21 : "... K-corrected rest-frame B-band ..." --->
          "... K-corrected, stretch-corrected rest-frame B-band ..."

          In fact, you are not very careful in this paragraph in distinguishing
          between m_B, as in the tables, and effective m_B as on the Hubble plots.

    p34 : The beginning of section 5.5 has to be reconciled with our current extinction
          treatment.

    Intermediate:

    Abstract: The phrase "there is no trend of anomalous E(B-V) ..." seems out of
              place. Would it be better at the end of the abstract? Or maybe
              break the last sentance at "yielding ..." and inserting the anomalous
              E(B-V) as a full sentance. Then start a new sentance. "Our analysis
              yields cosmological results ..." This last sentance is then a summary
              for the full abstract, not just for the extinction corrected analysis.

    p 7: "To ensure proper photometry the PSF ..." --->
          "The PSF ..."

    p10: "SN Ia spectra (described below)." --->
          "SN Ia spectra (described below) through the filter response."

    p12 figure 1 & 2: Isn't Figure 2 really just Figure 1? You are just repeating
                      the figure caption in any case.

    p13 eq 2: is it now 1/s^3 ?

    p17: "0.04 magnitude of intrinsic $U$-$B$ disperion (see below)." --->
          "an additional 0.04 magnitude of intrinsic $U$-$B$ disperion for $z>0.7$ (see below)."

    p17: "either in the proper value of R_B to use, or in ..." --->
          "either in R_B, or in ..."

    p22 figure 5: A few things to think about - the HST points, not the rejected points
                  should be highlighted. Also, the zoom box misses two of our SNe. The
                  totally reject points don't seem like they should be shown. All the
                  P99 data should be lighter or something, since otherwise all the noisy
                  points get the attention (binning would be another approach.)

    p28 : There might still be confusion in the readers mind between the 2dFGRS results
          we use and what Spergel used. Maybe a footnote at the end of the first
          paragraph end on the right side, to the effect

          "Note that we have not used the independent 2dFGRS power spectrum constraint
           on $\om h^2$ because it has not yet been generalized for different
           values of $w$."

    p34: The sentance "Possible evolution in ... our measurement" is redundant with the
         preceeding sentance.

    Minor:

    p2 : "... 265.A-5721) Based ..." ---> "... 265.A-5721). Based ..."

    p3 : it would be better if ""Fit E" of P99" and Riess references were swapped
         at the end of the last full paragraph in the left column. I understand
         that \cite might not offer this option.

    p3 : "were it found to systematically differ at different redshift would IT
          introduce a systematic ..."

    p4 : "... the equation of state parameter for dark energy, ..." --->
         "... the dark energy equation of state parameter, ..."

    p4 : "... uncertainties are presented for these ..." --->
         "... uncertainties for these ..."

    p4 : At the end of the last full paragraph on the right, you might want to add
         "Weather conditions allowed us to obtain spectral confirmation for only 50\%
          of the candidates for the 1998 search." Or something like this to convey
         that/why that search was not flux-limited.

    p5 footnote : "... the position uncertainty times the flux uncertainty, ..." --->
                  "... the product of the positional uncertainty and the flux uncertainty, ..."

    p7 : It looks like there is no space in "approximation---" or in "CCD---"

    p7 : I suggest starting a new pargraph at "Ground-based photometric calibrations ..."
         since this discussion is distinct from the rest of the paragraph.

    p8 : "... to the R and I band data." --->
         "... to the R- and I-band data."

    p8 : "... The peak B band magnitude ..." --->
         "... The peak B-band magnitude ..."

    p8: "... to the fit V band magnitude ..." --->
         "... to the fit V-band magnitude ..."

    p8: It wasn't clear why both R- and I-band zeropoints were allowed to vary for 94G.

    p10: "(e.g.) R-band filter" --->
         "(e.g., R-band filter)"

    p13: "There data were plotted together ..." and "... fit to the plot ..." sound like
         by-hand fits. Reword to reflect the actual implemenation.

    p13: I suggest starting a new paragraph at "As the goal was ..."

    p13: "the literature in Table 6." --->
         "the literature, as given in Table 6."

    p16: "Section 5.4" ---> "\S 5.4"

    p16: I suggest a new paragraph beginning at "Any intrinsic uncertainty ..."

    p16: "the result from the ..." --->
         "the peak color from the ..."

    p19: "supernoave"

    p21: "Figure 5 show all of the data in ..." --->
         "Figure 5 shows all of the data for ..."

    p21: "Figure 6 show just ..." --->
         "Figure 6 shows just ..."

    p21 figure 8 caption : "from the previous sample" ---> "from the P99 sample"
        
    p23 figure 6 caption : It seems there needs to be a more visible demarkation in
                           the caption between the discussion of the upper and lower
                           figures. You are counting on someone carefully reading
                           the caption!

                           Also, I suggest "three example model" rather than "three
                           different model", since I think the reader might be more
                           likely to think they have to chose a model with the current
                           phrasing.

    p26: "The top row ..." ---> "In the top row ..."

    p27 figure 9 caption : "top row represent" ---> "top row represents"
                          
    p29 figure 11 : Can the plots be laid down so that the w = 0 label is always shown,
                    rather than the w = -2 label?
                   

    p34 : "examine the size of ..." --->
           "examine the scale of ..." (since we later deny this the is actual size)

    p35 : "$\sigma_{\delta}=0.01$" --->
          "$\sigma_{\Delta\om}=0.01$"

    p36 : "which lightcurve width corrections ..." --->
          "which lightcurve-width corrections ..."

    p37 : "along the small ..." --->
          "along the minor ..."

    p37 : "cosmologcial"

    p37 : "exctinction"

    p38 table 9 footnote b : excise "measurements of \om and w" so this statement remains
                             generalized to parameters which constrain the combination of
                             Om and w.

    p38 table 9 footnote c : "enters in as" ---> "enters as"



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