Subject: Re: NGST IFS-MOS trade-off for AWG Date: Mon, 1 Feb 1999 00:22:05 +0000 (WET) From: lefevre To: R A E Fosbury CC: ghasinger@aip.de, sam@ll.iac.es, Olivier Le Fevre , Peter Jakobsen Dear Bob, Yes, this sounds fine. My main concern is the definition of the science cases we want to base the comparison upon. I've had an interesting session with the NASA Guys (Burg, Bely) on Friday, we agreed that the dimensioning cases are: - galaxy redshift survey of all galaxies in 1deg2 at the depth of 10000sec - survey of 100 cores of clusters of galaxies - survey of 2D fields (velocity, gaz / stars distribution, merging) for a sample of galaxies. These cases need to be defined in details. I'll try to work on this next week. What do you think about these cases ? I beleive the multi-slit instrument from McKenty is relatively well known, or sufficiently for the comparison purpos with FOV 3x3 arcmin2 and 0.1 arcsec elementary pixels (from micro-mirros array). All the best. Olivier ----------------------------------- Olivier Le Fevre Laboratoire d'Astronomie Spatiale Traverse du Siphon B.P.8 13376 Marseille Cedex 12 TEL: 33 (0)4 91 05 59 85 MOBILE: 33 (0)6 08 90 50 43 secretaire: 33 (0)4 91 05 59 38 FAX: 33 (0)4 91 66 18 55 email: lefevre@astrsp-mrs.fr ----------------------------------- On Fri, 29 Jan 1999, R A E Fosbury wrote: > Dear IF_MOS team, > > Here is my understanding of what we have to do: > > 1) Prepare a presentation for the AWG in the 19 April. This should be > for the purpose of informing them about the issues rather than > attempting a solution. > > 2) Prepare the ESA SST for the IFS - MOS battles which will take place > in the summer. This activity does not explicitly involve Guenther - but > I'm sure he's interested... > > What do we have to do? > > - Make a qualitative description of the pros and cons of each > philosophy. This can probably be taken from what is in the study already > but we need to add the bits that concern reliability, observation > planning and operations. > > - Describe in general terms the nature of the instruments: FOV, > pixellation, resolution, detector area etc. This is easy for the IFS but > we are going to have to make some assumptions regarding the MOS. I can > contact John Makenty but I suspect that he won't tell me very much - > especially if he knows why we want the information! > > - Characterise the sky from what we know about deep imaging. This has > already been started by the study team, by Santiago and by me. For > further analysis of the HDF (N & S), I propose to work with Stefano > Cristiani who is part of the IFMOS study and is also just about to join > my group at the ST-ECF. To interpret this, we need estimates (a la > Santiago) of how deep we can reach with the different instrument > configurations. We also need to know something about the filling factors > achievable with the MOS designs. > > - Confront all this with the DRM and the team's additions to it. This is > probably the bit we need to work hardest on. It will be easy to lay out > the matrix but we will have to do some work to fill in the numbers. > > Olivier, are you happy if I work with Stefano as the main contact with > what the team is doing in these areas? Can we rely on you to point out > the work which the team has done or is doing of relevance to all of > this? > I'm happy to coordinate the information and (help) prepare the > presentation but it is unlikely that I will be available to go to the > AWG: I'm at the 2nd Decade meeting in Baltimore just before AWG and I > also have observing time around then. > > Santiago, can you provide us with all the numbers you presented > yesterday? > > Guenther - what is your opinion of the plan? > > All the best, Bob... > > PS, my 3 viewgraphs from Thursday are at: > > http://ecf.hq.eso.org/~rfosbury/ngst/ngst_documents/ESA_NGST_SST_Jan99.pdf > > -- > R A E Fosbury (Bob) > Space Telescope - European Coordinating Facility > rfosbury@eso.org, http://ecf.hq.eso.org/~rfosbury/ > Tel:+49 89 320 06 235 (o) +49 89 609 9650 (h) Fax:+49 89 320 06 480 > > >