From: Chris Lidman (clidman@eso.org)
Date: Tue Aug 24 2004 - 06:36:18 PDT
Hi Alex,
Thanks for the quick reply. As a follow up question, do you correct
the measured B-V colour in some way, since the B- and
V-band observations are taken at different dates?
Cheers, Chris.
On Mon, 2004-08-23 at 20:00, Alexander Conley wrote:
> Hi Chris,
>
> Thanks for reading the draft so quickly.
>
> I'll respond to your more substantive comments, and try to
> get the improvements you suggest into the text as quickly as
> possible:
>
> Section 4, 2nd comment (B and V at different times) :
> This turned out to be much less of an issue than I thought. I
> required that
> the B and V data points be within 0.1 days of each other. In order
> to
> get
> more points I had to loosen the requirement to 7 days. It appears
> that,
> at least for this data set, people never took a rest frame V
> observation
> except right after a rest frame B observation. I know that this is
> not the
> case for our latest ACS observations.
>
> Section 5: CMAG relations at high redshift
> I didn't actually use the goodness of fit critereon here, or require
> that the
> SNe have more than 2 points. I should have explained this better,
> but
> the real requirement is npoints > 2, sigma_beta < 0.5. SN2000fr,
> believe it or not, does NOT meet this requirement -- it's slope is
> rather poorly measured (sigma_beta = 0.66). I felt that SNe with
> very poorly measured slopes don't really contribute to the
> discussion.
>
> Section 6.1: Dispersion
> I was actually doing my best to not compare dispersions. I think
> that this
> issue is a quagmire, and am really hoping to avoid it. Lifan is
> working on
> a paper where he talks about this a lot.
>
> Section 8 : Slope fit to dispersions
> The S = 0.7 value is ignoring errors. Including the errors is a
> little scary
> because they are presumably rather correlated -- but you are
> probably
> right, I should at least try to do something with them.
>
> Section 8: npointsmin > 1
> The shift is mostly along the long axis (Omega_2), by about 1/4
> sigma,
> but there is also a component along the short axis of about 1/6
> sigma.
> In the normal fit, Omega_1 = 0.09 +- 0.11 , Omega_2 = 1.48 +- 0.81
> With npointsmin 2, Omega_1 = 0.11 +- 0.12, Omega_2 = 1.66 +- 0.97
>
> Other points: s_b = s_v
> This is an ugly issue. The short answer is that it doesn't matter
> for the
> CMAGIC fits, but plays a slighly larger role in the maximum magnitude
> fits. In either case it isn't a big difference. I feel compelled to
> do it the
> way that I did because if you believe in CMAGIC you also are forced
> to
> acknowledge that s_B != s_V for all SNe. But I should certainly try
> to
> clarify that it doesn't really affect the result.
>
> Alex
>
> On Aug 23, 2004, at 3:10 PM, Chris Lidman wrote:
>
>> Dear Alex,
>> First of all, congratulations. You have done an excellent job, and I
>> appreciate all the effort that have made in documenting your work.
>>
>> My comments are mostly of a minor nature.
>>
>> For the SCP exec.: I am comfortable with taking off the blind.
>>
>> Regards, Chris.
>>
>>
>> --
>> European Southern Observatory
>> Alonso de Córdova 3107, Vitacura
>> Casilla 19001, Santiago 19
>> CHILE
>>
>> Ph. +56 2 463 3106
>> FAX +56 2 463 3101
>> <comments_23082004.txt>
-- European Southern Observatory Alonso de Córdova 3107, Vitacura Casilla 19001, Santiago 19 CHILEPh. +56 2 463 3106 FAX +56 2 463 3101
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