From: Chris Lidman (clidman@eso.org)
Date: Mon Mar 08 2004 - 13:23:15 PST
Hi Andy,
Thanks for going through these doubtful cases. From the plots, I'd
conclude the following
S01-004 IIb? - I've cc'ed this e-mail to Rob as he may be able to tell
us if this one was followed photometrically.
S01-028 ? - classification unchanged
C02-028 ? - classification unchanged
SuF02-002 - classification unchanged
Hence, with the possible exception of S01-004, the classifications
remain unchanged.
Cheers, Chris.
On Mon, 2004-03-08 at 17:53, Andy Howell wrote:
> Chris,
>
> I have mande several improvements to my program recently, most notably
> better outlier rejection and better handling of error spectra, so it
> certainly is worth rerunning objects for which we have questions. In these
> plots, blue is the rebinned spectrum after host galaxy subtraction
> (usually 5 A binning for these plots), black is the low-z template, and
> green is the original data.
>
> I have attached 5 postscript plots of the best fits to the 4 SNe you sent.
> > S01-004 - currently classified as ?
>
> Rerun with no host. The fit here shows a comparison to SN 1993J at +17d
> at z=0.41 (z is not known from the host). The fit isn't that bad. Do we
> know the date our spectrum was taken with respect to maximum light? I'm
> sure +17d is too late, but these IIb's have different features come in at
> different times depending on the relative thicknesses of the H and He
> envelopes. I wouldn't say that it is either a II or Ib for certain, but I
> think it is unlikely that it is a Ia. How about (IIb?) for the
> classification?
>
> > S01-028 - currently classified as ?
> > Significant host contamination. The percentage increase is only 27%.
> > Previously, we had this one as Ia?
>
> As you say, the host contamination is pretty bad. Here I show a
> comparison to SN 1999ee (Ia) at -8d after subtraction of an SB6 host
> galaxy. I find it very unconvincing. CaII should be obvious but is
> not. Still "?" as far as I'm concerned.
>
> > C02-028 - currently classified as ?
> > Another one with significant host contamination. The percentage increase
> > is only 13%.
>
> C02-028_spec.1.ps shows the comparison to SN 1999aa at -1d.
> The blue side looks ok, and it is possible that the feature at 9000A is Si
> 6150. The problem with this interpretation is that the SII "W" at rest
> 5400A should be there, but it isn't! Neither is the "emission" (really
> lack of absorption) just blueward of it at rest 5100A.
>
> C02-028_spec.18.ps shows a comparison to SN 1987K (II) at +7d after some
> serious host galaxy subtraction and mangling of the color. I don't
> believe it either, but it shows the difficulty in narrowing down the type.
>
> > SuF02-002 - currently classified as ?
> > This one has some host contamination. Previously we had Ia?
>
> Ugh. This one is disgusting. About the only thing I can say is that it
> is not inconsistent with a Ia. But on the other hand, there isn't
> anything to make me believe it is a Ia either!
>
> -Andy
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