June 28, 2002 from: C. Carilli (NRAO), S. Rawlings (Oxford) to: Chairs of ISAC Science Working Groups re: Pre-Groningen reviews cc: ISAC members, Peter.Hall@csiro.au, Ron.Ekers@csiro.au To the ISAC working group chairs and other members, Most of the SKA white paper (WP) design proposals have been received by the engineering management team (EMT), and the list promises to be complete by July 1. A total of 7 proposals are expected. The proposals can be found at: http://www.atnf.csiro.au/projects/ska/emt/Knowledge_Bank/Documents/system_definition.html The goal for the Groningen SKA meeting is for the EMT and the ISAC to evaluate the proposals, and delineate the merits and deficiencies of the designs. The proposers will then revise their designs based on these suggestions, leading to a final design review and choice by the end of 2005. In order to facilitate discussions in Groningen, the EMT and ISAC would like to make preliminary evaluations of the WP designs prior to the meeting, and communicate these to the proposers. We are asking the ISAC working group (WG) chairs for their assistance in the preliminary WP design reviews during the month of July, with help from the ISAC members of their WG. Much of the ground work has already been done in the Berkeley and Bologna meetings, as per the summary reports (http://www.skatelescope.org/ska_memos.shtml). This includes summaries of level 1 science drivers, and their demands on telescope design. We would ask that the chairs and group members review these reports to ensure that no major area has been overlooked. In parallel, Steve Rawlings and I are reviewing all the documentation, including the 1998 science case document of Taylor and Braun, and the 1999 Amsterdam meeting proceedings (ed. van Haarlem) to look for major science themes that have fallen outside the rubrics of the current working groups. Once the WGs are comfortable with the level 1 science goals and specs, we would ask the WG chairs to fill-out the summary form below in order to standardize the input. At the least, please fill out the 'requirements' column. But if time allows, you might also have a first pass at evaluating the designs in the context of the level 1 science goals. Steve and I will summarize the capabilities of each design with the week (the 'design' column below). We would like to have these reports from the WG chairs by the end of July, so that they can be collated and communicated to the proposers prior to Groningen. Throughout this process we should be considering where compromises could be made both in telescope design and science requirements. Please note such possible compromises at the bottom of the form. And remember, focus only on a few level one science goals per working group, ie. the absolutely must-do projects without which there is no sense in building the SKA. Please let us know if you are going to attend the Groningen SKA meeting. Most importantly, if you are a WG chair and are not coming to Groningen, please make sure that an attending member of your working group is 'seconded' as group leader for the meeting, and is well informed of the major issues. We were considering holding a telecon of the ISAC WG chairs, and other interested members, the first week of July to address questions that may arise in the review process. A proposed date for such a telecon is: July 3 at 8AM MDT (= 10AM Eastern = 4PM Europe = 11PM? Oz). Is such a telecon necessary? If so, is the time reasonable? Many thanks in advance and looking forward to seeing you'all in Groningen, Chris Carilli and Steve Rawlings ======================================================================== addendum 1: A list of working group chairs and email addresses. For new chairs, the old chair's address is also given in case you need information, such as previous group membership or notes from Berkeley. Working Group Chair ------------- ----- Intergalactic medium L.Feretti lferetti@ira.bo.cnr.it Life cycle of stars S.Dougherty Sean.Dougherty@hia.nrc.ca Early universe and LSS F.Briggs fbriggs@astro.rug.nl Transient phenomena J.Lazio lazio@rsd.nrl.navy.mil Spacecraft tracking/telemetry D.Jones dj@sgra.jpl.nasa.gov Galactic and nearby galaxies J.Dickey john@astro.umn.edu old: psackett@astro.rug.nl AGN and supermassive black holes H.Falcke hfalcke@mpifr-bonn.mpg.de old: dj@sgra.jpl.nasa.gov Galaxy formation T.vd Hulst vdhulst@astro.rug.nl old: ccarilli@nrao.edu solar system science R. Redman (proposed) old: none ========================================================================= Addendum 2: template summary form. Entries under 'design' column are 'dummies' based on the SKA straw-man design of 1998. ------------------------------------------------------------------------------ Level 1 science program: Title and text here Spec Requirement Design fail meet exceed comments ---- ----------- ------- ---- ---- ------ -------- A/T m^2/K 20000 depends on freq FoV sq.deg 1 at 1.4 GHz Multibeam number 100 beam sep (deg) 100 low freq only # subarrays response time s Freq range GHz 0.3-20 Correlator: Bandwidth GHz 0.5+nu/5 # spec channels 1e4 full BW sampling time s Configuration: max baseline km 100 50% area baseline 10 T_b sens K 1 at 0.1"res #independent IFs 2 max sep of IFs DNR: spatial 1e6 spectral 1e5 polarization 1e4 # spatial pixels 1e8 ----------------- Special requirements: (eg. transient buffer, continuous source visibility over 24hr, ...) Major problem(s): outline the major design problem(s) wrt science goal Possible Compromises: ------------------------------------------------------------------------------