From: Kyle S Dawson (KDawson@lbl.gov)
Date: Fri Jan 26 2007 - 08:23:43 PST
That first comment is very interesting. That claim for lack of dust in field E at high redshift can really help our cause for
using field E hosted SNe in our dust-free cosmology analysis. We have three very nice lightcurves of such SNe.
----- Original Message -----
From: Piero Rosati <prosati@eso.org>
Date: Friday, January 26, 2007 7:52 am
Subject: Re: new version of HST proposal posted - COMMENTS
To: Tony Spadafora <ALSpadafora@lbl.gov>
Cc: HSTclusterSN@lbl.gov
> Hi everyone,
> fantastic proposal!
>
> I have 2 comments, 1 correction and a question for Marc regarding
> Fig.
> 3a:
>
> 1)
> Regarding the evidence of no or little dust in ellipticals, we say:
>
> "Recent Spitzer data (Temi et al. 2005) confirms that most nearby
> ellipticals have the SED’s expected for dust-free
> systems."
> This was also found in early-types at z~1, and I think it would be
> worth mentioning it.
> Rettura et al. 2006 (A&A 458, 717-726) used SED fitting with 10
> bands, including the 4 IRAC bands, of 30 early-type galaxies at
> 0.8<z<1.2 in the field (mostly GOODS) and showed evidence of *no or
>
> very modest dust extinction*. This is the relevant paragraph in
> that
> paper, just to save you the time:
>
> We have also investigated the effect of dust extinction on the best-
>
> fit photometric-stellar masses by including a fourth free
> parameter,
> 0.0 < E( B − V ) < 0.4, following the Cardelli et al. (1989)
> prescription. By performing the fit on 28 galaxies for which IRAC
> photometry is available in all 4 bands, we find that in ∼40% of the
>
> cases E( B − V ) 0 gives the best fit. In the remaining cases,
> masses which are lower by 0.2 ± 0.1 dex are found, with
> corresponding
> E( B − V ) ≤ 0.2. This test supports the validity of the dust-free
> model assumption, as also widely used in the literature for early-
> type galaxies.
>
>
> 2)
> Mass-richness relation plot. It's nice, and the scatter/outliers
> not
> surprising given the nature of any richness parameter. We don't
> want
> to give the impression though this will be the kind of plots which
> will provide the "mass calibration" of future Xray/SZ surveys. Best
>
> mass indicators are currently physical quantities extracted from X-
> ray and SZ observations: T, Mgas, Lx,Y, Yx (the so called
> Yx=Tx*Mgas
> being the most fashionable these days). I doubt that anyone will
> use
> n_gal in the era of precision cosmology. This is mentioned at the
> end
> of the Cluster Science section (pag.6) but it should rather be
> here.
> So I think we should add in this section something like:
>
> Chandra and XMM observations of these clusters already in hand and
> upcoming SZ observations will allow us to probe for the first time
> at
> 1<z<1.5 the relation between fiducial lensing masses and physical
> parameters derived form X-ray and SZ measurements (Lx, Tx, Mgas,
> Y).
> These relations provide the critical calibrations for precision
> cosmology with next generation cluster surveys.
>
>
> -Correction:
> Pag.6: The GTO program has *four* clusters at z>1
>
> -Question for Marc: the caption of Fig.3a (VLT based CMR) reads
> "CMR in this same cluster using data from the VLT FORS and ISAAC
> (transformed to the ACS i,z passbands)"
> FORS has already i&z bands, how did you use ISAAC (J&K bands) to
> "transform" to ACS i&z ??
>
>
> Piero
>
> On Jan 25, 2007, at 11:32 AM, Tony Spadafora wrote:
>
> > Cluster search group,
> >
> > The working draft of the cycle 16 proposal on
> >
> http://supernova.lbl.gov/HSTclusterSN/proposals/HSTc16/clusters/text/> (HSTclusterSN/HSTclusterSN)
> >
> > has Wednesday's reworking of various sections. Comments are
> > welcome. There are still embedded internal questions and ?'s in
> > various places. Sci Just will need to be cut a little (~11
> lines).
> > Some of the figures need work. All of the captions and references
>
> > will need to be checked.
> >
> > -Tony
> >
>
>
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