Friday, February 21, 2003 from: C. Carilli (NRAO) to: ISAC re: Minutes from ISAC telecon Thursday February 20, 2003 cc: Tarter, Schilizzi ---------------------------------------------- Attending: C.Carilli, S.Rawlings, F.Owen, D.Backer, H.Falcke, D.Jones, C.Lonsdale, S.Doeleman, E.Sadler, R.Taylor, C.Jackson, F.Briggs, L.Blitz, D.Bock, B.Gaenslar, S.Dougherty, J.Lazio, J. Dickey, R. Schilizzi Agenda: 1. Final Matrix Review -- SR 2. ISAC plans leading up to Geraldton 3. Science retreat --- 0. The telecon opened with a short note from Leo Blitz concerning redshifted CO and the SKA. He emphasized that the large FoV and the 10x sensitivity relative to ALMA (even taking into consideration thermal line excitation) make it a preeminent instrument for studying the evolution of star forming galaxies. He and a colleague will consider this question in more detail and produce an SKA memo in the near future. He also said that discussions of science priorities should not be divorced from financial considerations. --- 1. Steve Rawlings led the discussion of the compliance matrix review. Revised inputs have been received and implemented for all the science topics except: Geodesy, EoR, CME's, Solar system. Dayton Jones agreed to look into Geodesy. Lonsdale and Lazio will look into CME's. Carilli will look into solar system. A substantial discussion was had concerning the EoR in the light of the recent MAP results and the advent of 'early reionization' (z = 10 to 30), led by F. Briggs. The basic results (Gunn-Peterson => 1% neutral at z=6.4 and polarized CMB => 50% ionized at z=20) suggest that reionization was a complex process that proceeded over a relatively large redshift range. While the promise for 21cm studies remains rich, new calculations/models/simulations are required to get a better handle on what early (or double) reionization might mean for the 21cm signal, and at what frequency. For instance, if the signal drops into or below the FM band, detecting it may be problematic. Schilizzi recommended the working group reconsider the current SKA specification in light of the MAP result. The issue was also raised again about LOFAR overlap on this issue, or a 'LOFAR upgrade' as part of the SKA plans. The general consensus was that the designs have to be evaluated as proposed, but that we do not want to drop the EoR from the SKA science case. Lonsdale questioned the rational for wide bandwidths and pulsars. Owen broadened the discussion to include SETI and the general issue of how to incorporate non-standard signal processing into the compliance matrix. The stated requirements may not convey enough information to be relevant in this area. Carilli pointed out that one of the main questions of the ISAC to the WP proposers in the October report was that they be more explicit on the signal processing capabilities of their designs. Considering the above issue, all agreed that having explanatory paragraphs associated with the matrix, especially for 'hard No' entries, is essential. In most cases the input can be very simple. Rawlings will incorporate these next week. Falcke suggested that for any hard No entry one should be able to access easily (with a 'click') the explanatory paragraph describing why. It was again pointed out that some non-compliances are 'soft' (eg. minor configuration changes), while some are 'hard' (eg. lack of frequency coverage). In most cases the current matrix does not delineate a 'soft' non-compliance as a hard No, but there may be a few exceptions. It was suggested that, where possible, the design proposers should be more quantitative (in terms of cost) when considering improvements that would turn a soft No to hard Yes. For instance, the Chinese design could get a larger field of view with a larger focal plane array, but at what cost? On the other hand, we must be careful not to have the proposers perform too many parallel tasks -- many design topics, such as fiber communications, are common and could be done by one or two groups, or by a coordinated effort. In summary, Steve Rawlings will make the final changes to the matrix this weekend. The WGs are encouraged to have one last look for consistency/correctness, at which time the matrix will be opened to the ISSC to be communicated to the proposers. --- 2. Carilli outlined plans for the ISAC up to and including Geraldton. a. By end of May revised white paper designs will be received, and a second review by the ISAC and EMT will occur in June. There is not much time, but hopefully the process will be simpler than for the original proposals. b. Carilli and Rawlings are outlining chapters and authors/project teams for the revised SKA science case document based on the original version, plus discussions by the ISAC over the last 2 years. They will present their plan to the ISAC for revision by mid-March. c. The ISAC plans in Geraldton include: (i) finalize the chapters/authors for the revised science case, (ii) present the plan to the ISSC/others, (iii) have a few preliminary science talks for working groups that feel prepared to do so. Current volunteers for science talks: Beck -- magnetic fields Lazio/Cordes -- transients Briggs/Carilli/? -- EoR: the revised model and SKA d. Carilli pointed out that there will be an SKA simulations session in Geraldton, and that there is a simulations group being formed in Australia that may be able to assist the working groups in the process of revising the science case, eg. the project teams can generate 'model skies', such as the 21cm signal from the EoR. These models are then given to the SKA simulations team who add realistic noise, UV coverage, and confusion to predict the capabilities. Lonsdale mentioned that MIT also has a simulations team who can perform a similar task. He volunteered to make a presentation during the simulation session in Geraldton. e. The long-term goal is to have a revised science case by May 2004. --- 3. Science retreat: Schilizzi described the currently confused status of the Berlin SKA/ALMA/OWL meeting, with the likelihood that it will be postponed until May 2004. Carilli/Rawlings/Schilizzi still feel an SKA science retreat would be in order, to 'jump-start' the science book revision process. This retreat should include ISAC members plus others involved in writing the chapters (the project teams). Carilli noted that Geraldton itself was not appropriate for science retreat due to the many other activities. A time/venue/funding are being sought. ---