Saul isn't back yet. Greg thinks he will get back tomorrow.
Gerson has been running SNe events through the fitting program, and has been busy plotting them. He starts by showing what Saul presented in a meeting earlier. Gerson doesn't agree with what Saul has now that we have more data. He plots a histogram of Omega_M in the flat universe for all SNe. Before, he showed us the plot with a peak at Omega of 0.3 or so, and with all of the old SNe to one side of that peak.
Based on the idea that the amount of light underneath the SNe may be correlated with how much extinction there could be, Gerson made a cut on SNe which have at least a 100% increase over the light that was under the SN before. (How well this is defined is a good question, since in the lightcurve software every image subtracts a different amount of host galaxy based on the relative seeing of data image and reference image.)
Gerson also tried using the Finkbeiner extinction (in the galaxy) rather than the B&H extinction. He did it to both Hamuy and our data. For the Hamuy data, it changed script-M by about 0.1 (the Finkbiner value is higher). The distribution is more or less the same... in other words, changing to Finkbiner extinction doesn't do anything since it changes both our calibration and our data. He is testing several other things which aren't quite ready, so he won't go into it.
Gerson also ran a Chisqr distribution in Omega for each of the SNe. (This should give you an idea of the uncertainty.) (Well, not really a chisqr, but something like a normalized uncertainty... Don suggests calling it Chisqr - Chisqr_min.) Gerson then showed us the sum of all those... which probably really is a Chisqr, which is a kind of a fit (weighted average?) to Omega_M in the flat universe. Result: Omega_M=0.41+-0.25, with no cuts, no host reddening correction, but with stretch correction. For stretches less than 0.8 or greater than 1.1, Gerson arbitrarily assigned stretch to the limit. Out of 38 SNe, he did this to 7 SNe. The asserion is that this didn't change the answer much.
Perhaps the most disturbing thing is that the first 7 were consistent within themselves, but the next 31 SNe give what seems to be a consistent answer that is lower.
There is some discussion of trying to figure out if our SNe and the Hamuy data have the same absolute magnitude distribution as our SNe. THere are issues of measuring absolute magnitudes and cosmology... but it would be interesting to see if there are non Gaussian tails (particularly on the "correct" side) in the distribution of Hamuy absolute magnitudes after stretch correction.
Reddening correction is also a problem; when Gerson tries to apply it based on our colors, the scatter goes way up. It could be just bad color measurements, which we probably have. However, I anyway have worries about how well we really know SNe colors, and the colors of stretches and such.
CFHT run. Not clear what we can do with these SNe, since we have absolutely no followup time. Susana believes that we have no spectra time; there was talk at one point of having WHT spectra time, but it didn't materialize. Also, there was talk about EROS followup, but it's not clear if anybody kept track of that.
The reason to do the CFHT run would be to show to them that, look, yes, we can find SNe on your telescope, we know what we're doing.
Intergalactic exctinction in dust associated with intergalactic hydrogen. Greg did the calculation, expects a few hundredths of a magnitude, which we wouldn't be sensitive to. (This isn't well known, however.)
Greg says that Robert looked at SN host color vs. SN color and vs. SN stretch, and so far there are no trends.