VLT Data files:

Date: 10 November 2002
Exposure time:
Data reduced by: Chris & Gaston
Weather note:
z (gal): 0.845? (old) 1.478 from [OII] (new)
z (SN):
SN (Chris final reduction 2): [fits]
SN (preliminary): [asc] [fits]
Line cleaned SN (preliminary): [asc] [fits]
Lifan's comparisons (preliminary): [ps] [ps] [ps] [ps] [ps] [ps] [ps]


Gaston (preliminary): Red object. No features. Galaxy line 9236AA --> z=0.845 (?)

Gaston (preliminary): We have tried the infrared technique for sky subtraction on SuF02_081 but our result is not any better than what we've got yesterday. We probably ought to refine our implementation. Looking at the spectrum we notice that, under the hypothesis that the galaxy line is [OIII] 5007, the redshift would be 0.85 -which makes more sense if we consider the discovery magnitude of this object- and the match to a SN+galaxy wouldn't be worse than that at z=1.48. The prominent feature we see at 7450 would land on 4000AA restframe, where a Ia at max would peak. The other dips that are less noticiable are in agreement with that redshift.

Saul (preliminary): Yes, we had looked into various alternative identifications of the lines, but in the end the evidence was very strong that the galaxy is at z = 1.48. There is a good match to the Magnesium line also, and the elliptical or Sa galaxy fits to that redshift even when you ignore the narrow lines. Note that we have never seen [OIII] 5007 by itself and that a number of other lines should also be seen if [OIII] is present, but none of them are there. At z=1.48, the galaxy + SN, with the appropriate ratio (when compared to the percent increase) is a consistent fit with the data. (Have a look at the fit that Lifan should be putting in Berkeley right now. So, it's not that the additional identification of the extra light beyond the galaxy light as due to an SN Ia is conclusive, but just that it seems to be the best bet. It would still be very interesting to see if there are other SNe that have the same feature that SN Ia have that makes the fit better.

Peter (preliminary): Redshift uncertain, SN spectrum very questionable (as even in their hope of matching it to z=1.5 still misses a big feature). It also misses the first Nic observation, though it looks like if we push the orientation to the far side of what's allowed it should work. We will ask Ray Lucas about this shortly. Grism observations can not work on this one as it is too faint.

Chris (Chris final reduction 2): z=1.478 from [OII]

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