From: Chris Lidman (clidman@eso.org)
Date: Fri Mar 12 2004 - 07:53:02 PST
Hi Rachel,
That will be great.
I re-checked SuF02-060, and the redshift from H and K in the
host (z=1.063) is accurate.
Cheers, Chris.
On Thu, 2004-03-11 at 23:55, Rachel G. wrote:
> Hi Chris and Andy,
>
> I will send you the ACS spectra for both SuF02-012 and
> SuF02-060 tomorrow. I realize I need to recalculate the
> error spectra since my last reduction.
>
> In the meantime, I've attached plots comparing the ACS
> spectra to the various ground-based spectra :
>
> SuF02-12 :
> figs 1-2 = Subaru
> figs 3-4 = VLT
> figs 5-6 = Subaru+VLT
>
> SuF02-060 :
> figs 7-8 = Gemini
> figs 9-10 = VLT
>
> Also included are Lifan's best matches (figures 11 &
> 12).
>
> N.b., Lifan wants to do a more careful galaxy
> subtraction for both of these candidates and for SuF02-060
> use a finer redshift grid when fitting - he used bins of
> 0.01. I'll let him elaborate.
>
> We think the redshift determination for SuF02-012 is
> quite robust and = 1.28. The redshift of SuF02-060 is
> 1.04-1.05. This latter spectrum clearly contains host galaxy
> light which is relatively bright, contributing more than 50%
> of the flux in Lifan's fits.
>
> Interesting also for this candidate is that there could
> be contamination in the ground-based spectra from a second
> galaxy which is pulling the fits towards a slightly higher
> redshift (see figs. 13-16) -- whereas the ACS spectrum
> doesn't suffer from this problem (fig. 17). Furthermore (to
> make nice figures) I had to apply a linear renormalization
> to the ground-based spectra in order to better match them to
> the ACS spectrum.
>
> Regarding the ESI spectrum, I believe Lifan has those
> data?
>
> Rachel
>
> On 11 Mar 2004, Chris Lidman wrote:
>
> > Hi Rachel, Vallery,
> > Could either of you provide Andy with the ACS spectrum of SuF02-012
> > together with an error spectrum. It might be interesting to combine
> > the ACS/VLT/Subaru spectra into a single spectrum.
> >
> > Does anybody know who reduced the ESI data on SuF02-012?
> >
> > Cheers, Chris.
> >
> > On Wed, 2004-03-10 at 13:37, Chris Lidman wrote:
> > > Hi Andy,
> > > Thanks for the plot.
> > >
> > > The Subaru data is available from http://www.sc.eso.org/~clidman/#L2742
> > >
> > > I weighted the VLT and Subaru spectra (using the error
> > > spectra) before combining them. In principle, one could add the ESI and
> > > ACS data as well if the the error spectra for these supernova are
> > > available. The ACS data appear to be in good agreement with
> > > the VLT and Subaru data. I know very little about the ESI
> > > data. You might have to ask Rachel, Vallery and Greg about the
> > > ACS/ESI data.
> > >
> > > Cheers, Chris
> > >
> > >
> > >
> > >
> > >
> > >
> > > On Wed, 2004-03-10 at 11:52, Andy Howell wrote:
> > > > You are right -- I attached the wrong plot! Here is the correct one.
> > > > The ACS plot looks pretty good.
> > > >
> > > > Your first mail said that it was a combined Subaru and VLT plot. I didn't
> > > > even know there was Subaru data on this one. According to the
> > > > spectroscopy web page we have ESI data as well.
> > > >
> > > > Any chance you could make a combined ESI, FORS1, Subaru, ACS spectrum,
> > > > maybe combining weighted by the errors? I think Peter has a program to
> > > > do such a thing. If not, if all of these have error spectra, I could
> > > > write something to do the rebinning and combination -- I have most of the
> > > > framework already for my program.
> > > >
> > > > -Andy
> > > >
> > > > On 10 Mar 2004, Chris Lidman wrote:
> > > >
> > > > > Hi Andy,
> > > > > Thanks for the plots. The first one seems to be a plot
> > > > > of SuF02-002. Perhaps, you attached the wrong PostScript file.
> > > > >
> > > > > I've cc'ed this e-mail to Rachel and Vallery as both have been
> > > > > involved in the reduction of the ACS data on this elusive candidate.
> > > > >
> > > > > I attach a comparison plot of the VLT/ACS data that was sent to me
> > > > > by Vallery. The ACS data also show a dip at ~9200 Angstroms.
> > > > > If this is Si4000, then this might point to a type Ia at z=1.26.
> > > > >
> > > > > Cheers, Chris.
> > > > >
> > > > > On Tue, 2004-03-09 at 21:46, Andy Howell wrote:
> > > > > > Chris,
> > > > > > This spectrum is better! I get z ~ 1.26, or z ~ 1.02 (see attached). I
> > > > > > prefer z=1.02.
> > > > > >
> > > > > > -Andy
> > > > > >
> > > > > > On 8 Mar 2004, Chris Lidman wrote:
> > > > > >
> > > > > > > Hi Andy,
> > > > > > > I've combined the Subaru and VLT spectra of SuF02-012 into a
> > > > > > > single spectrum. The spectrum and the associated error spectrum are
> > > > > > > available at
> > > > > > >
> > > > > > > http://www.sc.eso.org/~clidman/
> > > > > > >
> > > > > > > This candidate has been placed at various redshifts, anywhere from
> > > > > > > z=0.9 to z=1.6. The wiggles in the combined spectrum are more
> > > > > > > pronounced, but finding a redshift will be hard.
> > > > > > >
> > > > > > > Cheers, Chris.
> > > > > > >
> > > > >
> > > >
> > >
> > >
> >
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