SCP Meeting Notes - 2000 July 12

Agenda


NEAT/SNfactory update

Michael spoke about the latest stuff about NEAT/SNfactory. The data is currently being transfered from NEAT (MSSS) to JPL to HPSS (LBL). Headers are copied out at JPL and being sent separately to HPSS. At LBL those headers are grabbed from HPSS and loaded into the 'snfactory' database.

Saul asks if it makes sense to stop by Haleakala the first week of August (when Saul and Greg will be out to talk to people at the 88" (on Mona Kea?) about follow-up) to talk to the people at the NEAT telescope. Greg and Rob agree that we won't have a good handle on the actual data beyond some thoughts about a possible light leak. Saul agrees and says that maybe it's worthwhile to have a just-to-meet-you meeting.


CTE effect

Brenda has been working on CTE stuff and talking to STSci. How exactly do they doe the CTE effect calculations. What does the CTE effect depend on.

Dolphin finds no evidence for a long versus short anomaly. Stetson works with very crowded fields, Cepheid variables, which might lead to different results then the stuff we have. Saul argues that it might not matter because it's just like having a larger background. Adam Reis is doing a study of extended sources. Reis is sutdying galaxy clusters on different regions of the chip, doing aperture photometry and comparin diferences. He finds that there is a very local effect. The side of each galaxy which is closest to the readout is losing more charge than the side that is farther away. This is consistent with a picture of charge traps being filled up (taking their tribute). Reis also says that it's a very local effect.

Maybe the process is starting to accelerate and is non-linear. The comparison to photographic plates is that just as the silver emulsion requires several hits to ionize, the charge traps could require several hits to become a problem. Maybe their reaching that transition threshold right now.

Alex Kim says that IRAF has an 'apphot' routine. Saul asks how the centroiding was done (median vs. mean, etc.).

Brenda says that there are two different approaches to what she should be doing. Should she just use the other group's stuff, or should we do it ourself using the corrections published by others.

Alex asks to be reminded about the effect in our specific case. Brenda says 40% effect at max, 10% not unusual. Greg quotes 7% for a previous SN. Basically, we're screwed unless we figure out.

Saul brings up the question of zeropoint with CTE and aperture photometry. Greg will contact Stetson to get his update.


Miscellaneous


Tuesday, 9 a.m. - Video Conference call for HST proposal due in the Fall.
Thursday, 8 a.m. - Everything else (i.e. next Spring 2000)
Michael Wood-Vasey
Last modified: Wed Jul 12 15:12:03 PDT 2000