head 1.1; access; symbols; locks http:1.1; strict; comment @# @; 1.1 date 2004.07.29.08.32.10; author PaoloPadovani; state Exp; branches; next ; desc @none @ 1.1 log @none @ text @AVO meeting, July 21 2004, CDS Strasbourg ========================================== Notes: Mark Allen, Nic Walton; revised by Paolo Padovani Attendees: TB Thomas Boch LC Laurent Cambresy SD Sebastien Derriere PP Paolo Padovani NW Nic Walton MD Markus Dolensky PR Piero Rosati AR Anita Richards GR Guy Rixon MA Mark Allen Agenda: 1. review of the input the SWG provided for possible science cases to be implemented in the 2005 demo (stars and galaxies; the cosmology group concentrated on the Science Reference Mission [SRM]); 2. decision on which ones to adopt based on their scientific content and also technical requirements; 3. make definite plans and assign tasks; 4. if time allows, go through the SRM plans with the scientists (at the end of the meeting). ----------------------------------------------------------------------------- Galaxies sub-group proposals ----------------------------- MA & NW reviewed the Galaxies SWG sub group science case proposals. (see attached ppt slides). Ultra Compact Dwarf Case - Interesting, topical science - Initial discoveries done on highly customized data set (2dF all object survey of Fornax), and there appears to be no other relevant publicly available spectroscopic data set. - The selection procedure for Ultra Compact Dwarf galaxies from multi-band imaging data appears to not be specific enough. Main issues are establishing cluster membership and whether the properties of the objects, are enough to distinguish the objects. - Candidate objects have been found in Abell 1689 using imaging data and photometric redshifts. This works for Abell 1689 because it is at a distance at which photometric redshifts work. Also this uses a deep ACS imaging data set. - No relevant imaging data set has been suggested. - Summary - be good to make this work, but there are not enough specifics. Generic Galaxy Clusters Science Case - "Rich and merging clusters" proposed by Galaxies sub-group. - Lacks a focused scientific question, but looks like a good demo for showing off VO infrastructure. - General science areas: - Age dating latest merger event - Assessing stellar population parameters of cluster members as function of position in a cluster - VO aspects - data discovery - making a data inventory - Generating SEDs from catalog and image data - SED generator and SED tool needed - using wrapped web services in a workflow - Sextractor - Hyper-z - Swarp ( tool for re-gridding images onto same scale) - Stellar population parameter tools - Pegase - Starburst99 - GALEV / PASAT - using distributed work-space (myspace) - visualising results - General flow of steps is - Find imaging data (will need to be specified from beginning) - Find relevant catalogs - Do photometry on imaging data (multi-wavelength) - Will need regridding of data onto common pixel grid using tool like Swarp - Assemble SED from photometry and catalogs - Visualise SED - Compare SED to stellar pop models - may need to run grid of models or use available grid - need a fitting "tool" (?) to find best match model (this is of course a simplification of a potentially very complicated step which requires expertise on dealing with stellar pop fitting - i.e. assessing applicability of given sets of models) - Visualise SED and model (SEDs and spectra) together - Do something interesting with the fitted stellar pop parameters - eg. plot as function of radius in cluster (?) - What data do we use for this case? - Possible data sets may include INT Wide Field Survey (Database managed by Cambridge) SLOAN - include both spectra and images HST association data (raw archival data would require processing) ESO imaging survey data (EIS) GOODS - (again...?) - Given the uncertainties for scientific focus of this case, we could apply it to galaxies in general rather than just clusters of galaxies - Generic Galaxies case selected for demo, but lots of specifics need to be worked out. Stars SWG sub-group science case proposals ------------------------------------------ PP reviewed the Stars SWG sub group science case proposals. - "AGB to PN" case selected (see below) - Could also include "Search for IR excess in bright stars", as datasets are the same - Expect to get significant scientific assistance from Garcia-Lario (main proposer) - Mainly catalog driven, and looks very possible with existing tools, but requires some to be enhanced to accommodate large catalogs, and doing things on larger scale - Need to include Spitzer data, ISAAC would also be good Asymptotic Giant Branch (AGB) to Planetary Nebulae (PN) transition case: Overview (see http://www.euro-vo.org/twiki/bin/view/Avo/SwgStars for details) - Evolution AGB - Post-AGB - PN still poorly known and multi-wavelength analysis of large sample of stars in this short transition phase is needed to test current models. Issues: i) study of individual sources (see example of Henize 3-401) by the reconstruction of their SED by putting together information available (IUE UV spectrum, ground-based optical spectroscopy and photometry, near infrared JHKL'M photometry + ISO IR data (includes PHT-S + SWS) + IRAS photometry. ii) study of a well defined sample of sources selected on the basis of given MULTI-WAVELENGTH (multi-archive) scientific criteria in order to derive conclusions based on statistics. iii) Search for new sources in the transition AGB-PN combining existing photometric data in various infrared surveys (2MASS, MSX and IRAS). Spitzer? ISAAC? New sources in the transition AGB-PN can be found among the infrared MSX sources (8-21 microns) with no previous identification in the literature (SIMBAD). VO aspects of Jan 2005 demo ---------------------------- - Review of VO components relevant to demo - Conceptual architecture ideas Registries ----------- Registry functionality should be shown in demo if sufficiently mature, and useful - NVO registry was briefly demonstrated by GR - MD made a diagram of how Registries might work between an AVO demo portal (like Aladin), GLU, and the AstroGrid workflow and MySpace, and AstroGrid registry (and other registries) - In principle files in MySpace should be able to be resolved into URL locations which external tools could access. Other identifier schemes may also be better, using IVO identifiers, and possibly the AstroGrid "delegate" which may allow external writing to MySpace. SED generation and visualisation/manipulation ---------------------------------------------- Two main issues: SED tool, and SED generation from data. Data models - do not currently contain information relevant to generate SEDs from catalog or image data Current SED tool is "badly factored" - MD MD made diagram of possible flow of information for generating SEDs. MA asks where real conversion of photometry will happen because this is non-trivial. Discussion of whether an SED tool should also do the cross-matching. General answer no, keep that function separate. Problem of cross-matching across different catalogs will still need to be addressed. Data sets that we need to consider also include 2dF and Spitzer SED tool: discussion on possible use of VOPlot. SpecView may be the answer, I. Busko appears to be keen to implement our requirements. Model Fitting tools ------------------- What are we really going to use for this??? - no obvious solution yet. Action items ============= * Minutes of this meeting: MA, PP, NW * New demo development pages: NW, MA to begin * Flow diagrams: PP * Registry implementation: AstroGrid * Find data for galaxies case: MA, PR, NW * SpecView enhancements for SED: MD to ask Ivo Busko * Catalogs and science specifics for AGN-to-PN case: PP to ask Garcia-Lario * SED generator : ESO to make ESO data "SEDable" : All... ? * Model fitting capability: ? * Investigate large catalog handling for tools and X-match: SD * Investigate ADQL for CDS service (Simbad, Vizier?): TB, SD * Investigate harvesting of SIAP compliant service from registries for data access through Aladin : TB * Wrap SExtractor, PEGASE, Starburst99, Swarp as web service: AstroGrid * Investigate 'myspace/vospace' implementation at CDS, ESO: AstroGrid * Proto AVO/Euro-VO 'demo' portal: AstroGrid * Workflow issues - linking to CDS/Aladin: AstroGrid/CDS - Weekly telecons to resume in September (Sept 6, 3pm CST, dedicated to SRM discussion, scientists only) - Notify SWG at a suitable time (in a few weeks) - When flow diagrams are done, generate a full technical assessment for developments @