From: Andy Howell (DAHowell@lbl.gov)
Date: Thu May 16 2002 - 17:36:45 PDT
I reply to both Cris and Saul here, so read all the way down.
clidman@eso.org wrote:
>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.
>
Chris,
That is a very useful calculation. Unfortunately it seems to me that it
puts us squarely in the "what do we do" camp. The reason I say this is
that we can't take the 7 days before maximum number from the spectral
fit too seriously. We only have about 10 template spectra that cover
enough of the UV to match the z=1 SNe. That, combined with the low S/N
of the spectrum make epoch estimation very difficult. I understand that
there is little else you can do, but I just wanted to make that clear
everyone.
>Saul Perlmutter wrote:
>can someone look at the SN we have aspectrum 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.?
>
T02-037 is the SN at z=0.49. I assume by "low metallicity" you mean "UV
bright." Note that UV bright does not necessarily mean low metallicity,
and low metallicity does not necessarily mean UV bright. At any rate,
there is no evidence either way in this spectrum. It cuts off just
after calcium ~3700 A rest frame, so there is no UV. It would indeed be
nice to get a bluer spectrum just to see what it does. It is not clear
what we could do with the spectrum of just one object, but we do need to
start testing the hypothesis that we see more UV-bright SNe at high
redshift.
-Andy
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