From: clidman@eso.org
Date: Fri May 17 2002 - 02:36:42 PDT
Hi Saul,
If for arguments sake we use J=23.7 as the peak magnitude for a type Ia at z=1.1 and if S02-002
was 7 days before maximum on the 14/04/02 when the spectrum was taken, S02-002 would now
be about 8 days past maximum and the J band magnitude of S02-002 would be about J=24.
If the peak magnitude was closer to 24, which is a pessimistic assumption, then S02-002 will be around
24.3 by now and this is too faint.
I think Isobel reported that Gemini observed this target for 4.5 hours. Together with the ISAAC data, this comes
to 28,000 seconds of integration time.
I will ask Paranal to spend 3 more hours on this target, but I will ask them to do it only if the IQ on the images
is better than 0.5.
Cheers, Chris.
Saul Perlmutter wrote:
> Hello Chris and Everybody,
> I'm on my way to the airport, and just checking my email for five minutes before I have to head off to catch my plane
> home. So I don't have time to do the following checks to help figure out what to observe tonight and this week (if
> telescopes ever really open). First, and most important, can someone check to see if S02-002 is still bright enough for us
> to get another 6 hours or so on ISAAC to improve that signal to noise? Second, can someone look at the SN we have a
> spectrum for at z ~ 0.49 that has evidence of being very low metallicity, and see if we could get an interesting blue spectrum,
> in which case we might also want one or two hours of ISAAC
> on it.?
>
> clidman@eso.org wrote:
>
> > Hi Saul,
> > I provide a summary of what has been done with ISAAC to date.
> >
> > - S02-032, 31800 seconds, IQ=0.52, S/N=13
> > - S02-002, 12000 seconds IQ=0.46, S/N=8
> >
> > I have assumed that both supernovae have J=24. In both images he S/N of the candidate
> > is actually higher, which means that there is either host contamination, which is certainly
> > true for S02-002, or that the SN is brighter than J=24.
> >
> > The S/N is computed from the nightly ZP, the sky noise in the combined image and is for an aperture
> > with a diameter of 1 arc second.
> >
> > S02-002 was observed with Gemini as well. If the data is of similar quality, and I would expect that
> > the Gemini data is deeper, since they probably use the classical J filter, then we might have enough on
> > S02-002. It might also be a bit late for S02-002.
> >
> > ISAAC is in service until the 19th, which is a technical night. It is again in service from the 23rd onwards,
> > but only for the first half of these nights
> >
> > There is 7.5 hours of ISAAC shutter time left. This could be used for:
> >
> > - the z=0.912 supernova.
> > - a z=0.55 supernova (I do not have any in mind). To be meaningful scientifically, we would need good ground based
> > followup and one would like to do more than one supernova at this redshift.
> > - go deeper on the Beethoven reference (this would need 2 hours)
> >
> > It is not 100% clear to me if this time can be carried over to period 70. The OPC awarded the time for period 69, but since
> > we have large program status, we may be able to carry over some time. I will ask ESO.
> >
> > Cheers, Chris.
> >
> > Saul Perlmutter wrote:
> >
> > > Hello Chris, I forgot to ask you about the current ISAAC time. Did
> > > we get enough ISAAC signal-to-noise on the second z~1.1 SN from last
> > > month, the one you did most recently? Or should we try to get another
> > > 5 hours or so on it? I guess tonight is one of the options for this
> > > and then we have a few more nights, before it would be to late? Also,
> > > do we need to be scheduling this week's ISAAC time for any other
> > > targets, if we decide not to do this high-redshift target?
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