From: Chris Lidman (clidman@eso.org)
Date: Thu Mar 18 2004 - 09:56:14 PST
Hi Gerson,
Thank you for the information. This is very useful.
Could you spend a few moments describing the criteria you use
in classifying an object as a SN. Is it based on the goodness of
fit to the photometric data and the likelihood that the resulting
stretch is reasonable?
From your plot, I derive the following statements.
The four SNe which had been classified as Ia or Ia? from the VLT
spectroscopic data are classified as SN from the photometric data. They
are SuF02-017, SuF02-025, SuF02-060 and SuF02-065.
The two SNe which show significant wiggles in the spectroscpic data
but were not classified as Ia or Ia? because the S/N is too low are
classified as SN from the photometric data. They are SuF02-007 and
SuF02-012.
All Subaru candidates that have been given an IAU name are also
classified as SN from the photometric data.
There is one candidate (SuF02-002) that is classified as SN from the
photometric data, has a redshift, but is otherwise spectrally
unidentified. This candidate has significant host contamination.
There is another candidate (SuF02-051) that is classified as SN from the
photometric data, but has neither a redshift nor a spectral
classification. This object was faint $I\sim 25.3$.
There are five candidates which are not classified as SN from the
photometric data. Four of these are because they were not followed
and one (SuF02-081) is because the lightcurve suggests an unreasonably
small stretch. All five candidates could not be spectrally classified as
Ias.
Putting this in a table, one gets the following
Ia - Is very likely to be a Ia from the photometric follow-up
SN - Is very likely to be a SN from the photometric follow-up
Not a SN - Is probably not a SN.
Not followed
#ID IAU ID Spec. ID z Photometry
==================================================
SuF02-002 2002kq ? 0.823 SN
SuF02-005 - ? 0.863 Not followed
SuF02-007 - ? 1.16? SN
SuF02-012 2002lc ? 1.3? SN
SuF02-017 2002kn Ia? 1.03 SN
SuF02-025 2002km Ia 0.606 SN
SuF02-026 - ? ? Not followed
SuF02-028 - ? 0.347 Not followed
SuF02-051 - ? ? SN
SuF02-060 2002kr Ia? 1.063 SN
SuF02-065 2002ks Ia 1.181 SN
SuF02-081 - ? 1.478 Not a SN
SuF02-083 - ? 1.272 Not followed
==================================================
Hence the photometric and spectroscopic results are in good agreement
and it suggests that we discover and follow real SN, even at the highest
redshifts.
For the VLT spectroscopic paper, I intend to include something like the
following.
"The photometric followup of the candidates discovered during the
Fall 2002 search with Subaru shows that 8 of the 13 candidates
are likely to be supernovae from the light curves. These eight
supernova include four candidates that were spectrally
classified as Ia or Ia? and two candidates that show
spectral features that are consistent with a Ia classification
(SuF02-007 and 2002lc). Of the two candidates which do not seem to
have SN features, one has significant host contamination (SuF02-002)
and the other was extremely faint - it was the faintest of all
candidates that was observed at the VLT. In both cases, the S/N of the
spectra are not high enough to rule out a supernova classification.
Of the five candidate that were not photometrically classifed as
supernova, four were not photometrically monitored, so there is no
information to help in the classification, and one (SuF02-081) is
unlikely to be a supernova.
Hence, even at the highest redshifts, most of the candidates are
very likely to be supernovae"
Reynald, would it be possible to provide similar information about the
CFHT 2002 candidates.
Cheers, Chris.
On Wed, 2004-03-17 at 12:58, Gerson Goldhaber wrote:
> Hi Chris,
> I have info on these:
>
>
> SuF02-002 0.823 Subaru 17.39 54 24.14 SN
> SuF02-005 0.863 Subaru 10.76 16 24.57 not followed (as
> far as I know)
> SuF02-007 1.16? Subaru 5.86 >1000 25.14 SN
> SuF02-012 1.3? Subaru 5.85 118 25.17 SN
> SuF02-017 1.030 Subaru 12.15 >1000 24.61 SN
> SuF02-025 0.606 Subaru 18.33 89 24.31 SN
> SuF02-026 ? Subaru 11.26 28 24.83 not followed
> SuF02-028 0.347 Subaru 14.03 35 24.71 not followed
> SuF02-051 ? Subaru 8.29 >1000 25.27 SN
> SuF02-060 1.063 Subaru 16.98 25 24.46 SN
> SuF02-065 1.181 Subaru 12.55 34 24.80 SN
> SuF02-081 1.478 Subaru 7.92 69 25.14 ?? very narrow
> s=0.45
> SuF02-083 1.272 Subaru 6.08 19 25.10 not followed
> ========================================================
>
> Cheers Gerson
>
>
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