From: Chris Lidman (clidman@eso.org)
Date: Sun Dec 19 2004 - 12:59:22 PST
Hi All,
Actually, I forgot to attach the paper, but that is probably a good
thing. The latest version is available at
http://www.physto.se/%7Esnova/private/internal.html
Sorry for the spam.
Chris.
On Sun, 2004-12-19 at 17:53, Chris Lidman wrote:
> Dear All,
> I think that Rob and Eric have raised as issue that needs to be
> discussed on Tuesday.
>
> I attach the most recent version of Gaston's paper (version Jan. 22
> 2004). A description of the method that was used to determine the
> bounds over which features are measured is given in section 3.2.
>
> Gaston worked with spectra that had good S/N ratios and the
> description given in section 3.2 might be sufficient for such spectra.
> The spectra with the lowest S/N ratio in Gaston's paper has a S/N
> ratio of 5. Gaston did not find any systematic effects when the
> S/N ratio of the best spectra were reduced to such a level. This is
> reasonable.
>
> However, such a S/N ratio is probably higher than S/N ratios of
> most of the high-z SNe in Gabriele's paper. Hence, it seems reasonable
> to ask Gabriele or Gaston to check for systematic errors when the
> S/N ratio is reduced to the levels that are typical for high z SNe.
>
> For such low S/N spectra, it would seem that some sort of rebinning is
> necessary before features can be identified and measured. Gaston, were
> the high-z spectra rebinned before the EWs were measured?
>
> Cheers, Chris.
>
> PS The last message in the e-mail archive is dated January 26th, 2004.
> This e-mail contained the minutes of a meeting we had on Gaston's paper
> and it contained suggestions on how the collaboration thought the paper
> could be improved. Gaston, let us know if you are still out there. I
> might send a search party to La Serena to find you :)
>
>
>
> On Fri, 2004-12-17 at 17:10, Robert A. Knop Jr. wrote:
> > On Fri, Dec 17, 2004 at 11:59:45AM -0800, Tony Spadafora wrote:
> > > I've put more time for the evolution paper because this paper has been
> > > before the collaboration since July. The discussion here should be to
> > > confirm that all issues have been resolved (e.g. the systematics of the
> > > equivalent width determination) and, if so, that a submission-candidate
> > > version should be finalized and submitted soon.
> >
> > For the record: I'm not convinced at all that the systematics in the EqW
> > determination are resolved. So far, all that's happened is that the
> > issue has been raised. More basically, the method for determining
> > them from noisy spectra needs to be documented in the paper; all that
> > Eric and I have heard so far is that "Gaston did it" is the method,
> > which obviously isn't something one writes in a published paper.
> >
> > Gaston probably really needs to be at this meeting since he is the one
> > who knows how the measurements were made.
> >
> > There's also the issue that this builds on the nearby EqW stuff that
> > Gaston has done. If *that* paper isn't published first, then that stuff
> > will need to get incorporated into this paper for this paper to make
> > sense.
> >
> > Please include Eric on mailings for this, since obvously he is involved
> > with this. Also please re-send the schedule so he gets it.
> >
> > -Rob
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