Comments on February 6th draft

From: Chris Lidman (clidman@eso.org)
Date: Sun Feb 08 2004 - 05:48:42 PST

  • Next message: Serena Nobili: "Re: Comments on February 6th draft"

    Hi Serena,
       Good work! I have mostly minor comments.

    - Lifan Wang's 2003 paper (could I have a copy of this)

    - The errors in M_I(max) are of the order of +/- 0.15 magnitudes. They
    are significantly larger that the errors attributed to uncertainties
    quoted for I_1 (=I_max) in table 2. Am I correct in presuming that the
    major source of uncertainty in M_I(max) are the correction for
    extinction and the additional error from peculiar velocities?

    - At the end of the first paragraph in section 2.4, you say that the RMS
    for M_I in the M_I vs s_I plot is 0.21 magnitudes. It is not entirely
    clear to the reader if this refers to the dispersion without a fit,
    or whether this is the dispersion about a fit. This should be made
    clearer.

    - Figure 8 (which comes before figure 7) is too crowded. I suggest that
    you drom the Keck J band curve and just state in the text that it is
    similar to ISAAC Js. Note also that the drawing you have made is
    applicable to a SN at z=0.543 (ie Beethoven) and we did not use the Keck
    to observe Beethoven. Has the Bessell curve been corrected for the now
    famous lambda factor?

    - Table 5 - uncertainty in the ZP. The formal uncertainty is 0.01
    magnitudes, so the error is dominated by Poisson noise and the
    uncertainty in the ZP is negligible in comparison.

    - The I_max magnitudes in table 8 and I_max magnitudes in figures 9, 10
    and 11 appear to be slightly different.

    - Paragraph 4. I think that this paragraph should be removed as modern
    IR standard star systems are just as good as visual standard star
    systems. It comes down to the care the observer takes in choosing a
    suitable set of standards and to knowing how one standard star system
    relates with another. Thanks to 2MASS, the relationship between systems
    is better understood.

    - cases b, d, a, and c. I do not like cases b and d. I do not believe
    the systematic uncertainties should be ignored.

    - K corrections. Your k-corrections should be checked by an
    independent person.

    - Perhaps it can be stated why observations that are outside the range
    defined by Nobili et al are not included in the analysis. The curves in
    figure 13 go to -10 days.

    - figure 14. Dotted ellipses. I see solid and dashed ones only.

    I hope this helps. I'll talk to you later in the week.

    Cheers, Chris.



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