Mike has written a few centroiding programs, and he's in the process of testing them. Greg referred him to a paper by Stone that has some more centroiding options. He's playing with a few different things, and a few different algorithms and methods of doing this.
Gerson is going to a meeting next week and he's supposed to give a summary on the future of Cosmology. He raises the issue that the latest binary microlensing results suggest that the lensing objects are in the Magellanic clouds rather than in our halo. Gerson solicits a reference for this. It seems that the July 15 Science has some information on this, but that's the only reference that Gerson has. At any rate, it throws into doubt whether all the MACHO events are in our galaxy.
He's also going to talk about the Next Generation Space Telecope. He wants wisdom for the future cosmology that can be done with this. We brainstromed a bit. Mentioned hypernovae, redshift surveys, lensing projects, butt-redshifted supernovae, etc.
(This screen is flickering something awful. The laptop has become borderline useless. I really have to find out how much it will cost to service it, but I'm afraid: I've heard horrible things about how much it costs to replace laptop screens.)
Marcus' instructions on how to do what he's been doing. He's been working on functions to integrate cosmology equations. He's passing out short docuemtation, which points to web documentation at http://panisse.lbl.gov/groupwork/documentation/cosmo. All the routines are available; Robert helped him get them all into CVS and the deephome/idlpro directory.
Robert is still working on the Omega fit program. He's trying to find the slope of the countour of the ellipse on the Omega-Lambda plane, so that we can project the thing along (and perpendicular) to that line. That should give a better width of the ellipse.
Rob has accomplished nothing. He will switch the database real soon now (RSN). Don asks him about disks; we had a 18 Gig disk that didn't work. Things are all up in the air.
Don says that the Steve finished the third poly step. He has things left to do that he regards as trivial. His finishing is going to coincide with the Lick crew being in China for most of September. The probe cards have been ordered. Don is working on making a pair of tweezers to lift the things with. There are many engineering issues.
Don says there are five or six wafers (each of which has two 2000x2000 devices), although they all have a different status. Steve is holding some back while he proceeds forward with other (sounds wise).
Don says that EEV and Lincon labs are also supplying chips, with various degrees of thinning. He says something about field-free regions inside the chips. Thinning normally removes the part that is field-free. Don's opinion is that these somewhat thicker, high-resistivity chips, with no voltage applied, may have a terrible psf due to lateral diffusion. (Ours we bias, a lot.)
Don says any volunteers interested in working on this are greatly appreciated!
Alex hasn't been here since the last group meeting... he's been at class. That means he hasn't gotten much done in terms of figuring out what to do with the HST. He will work on it over the course of the next three days. We will come back to this discussion....
For the HST, we are discussing what we really want to apply for. The problem with morphology (what we thought we'd apply for) is that it takes a lot of orbits, and it doesn't sound really that sexy. Greg pointed out that you might spend more orbits trying to get hosts of old supernovae than you'd spend getting better new supernovae.
Greg mentioned proposing to do a set of supernovae at 0.8, and one at 1.3, with HST. The idea is that we would start making use of the U-band; from the nearby search, we hope to know a lot more about how the U-band behaves. At z=0.8, we get a U-B color from R-I... if we know how to use that for extinction, we can still do it. As for higher redshifts, the path isn't entirely clear (e.g. for finding them), it seems that over the period of HST cycle 8 there were be several options coming online. Perhaps CFHT will get its act together and we can search there, or Subaru will have a chip, or we'll have an LBL chip on LRIS on Keck, and so forth.
At z=1.25, with the HST you get a roughly U-band lightcurve, using WFPC in I-band. The case we'd have to make is that next spring we're going to do the nearby search and we'll get nice U-band lightcurves for 30 supernovae. We have preliminary evidence from Peter and Don that the U lightcurves stretch in the same way that the B lightcurves stretch. Cycle 8 will be mid-1999 to mid-2000, so hopefully we should have the nearby supernovae by then (and hopefully we can convince them of that).
The problem is that you have no color for the z=1.2-1.3 supernovae, and U-band is more sensitive to supernovae. What we would propose is that we would get a J-band point when the next generation of IR telescopes with AO come online.
Peter and Greg, using the exposure time calculator for the VLT, figured out that you could probably get a point on one supernova at z=1.3 with two whole nights, without AO. That's with stuff that exists at Keck already, and is going to exist at VLT. The optimistic estimate is that there will be AO online at Keck and at Gemini during HST Cycle 8. With those, we could probably get about 3 high-z supernovae in a night. However, even if we don't get AO, the whole thing doesn't fall apart.
As another deal, Greg thinks that since there are only three at z=0.8 and above, none of which have good colors, we can argue that there is still good science to do there. So, even if the 1.3 stuff falls apart, there is still good science to do at z=0.8.
A subissue is how to find these (0.8 and 1.3). You could find them with HST, or maybe LRIS. CFHT as is is more efficient than Keck as is. Subaru is another possibility. The trick is to convince them that we can find them, and have lots of avenues, without souding too vague about them. (Hopefully Reynald's 0.8 search is going to produce lots of 0.8's.)
Much gory discussion continues while Rob runs over to set up Tea. (10 minutes later he realizes he forgot to turn the water on.)
Greg is currently working on doing a catalog search of our existing WFPC data. He's still in progress working on this. There is discussion of trying to use our subtraction software on the HST images... Alex may attempt to push this through at some point. Rob thinks it would be possible, with some massaging.
Finishing this thought, Saul thinks we can put both proposals in, morphology and this. R. Ellis would spearhead the morphology. Saul says that there is no harm in having both proposals in.
Alex Filippenko sent in a beginning complaint on the paper. Saul is trying to address it now. Filippenko promises to send in more complaints in the next day or two.