1. July 13, 2004P. Padovani, The A-Star Puzzle1 A-Stars and the Virtual Observatory Paolo Padovani, ST-ECF/ESO AVO Science Manager The Virtual Observatory (VO) Europe and the VO: the Astrophysical Virtual Observatory A-Stars and the (A)VO: concrete applications Disclaimer n. 1: Big topic, good for a whole workshop Disclaimer n. 2: Extragalactic astronomer! The Virtual Observatory and A-Stars

2. July 13, 2004P. Padovani, The A-Star Puzzle2 Astronomy in the XXI century Radical changes are needed!  Huge surveys: 100M sources at 100 yr!  Ever fainter sources: surpassed the identification limits of 8 - 10m telescopes (R mag ≈ 25)25  Huge data collections: downloading Sloan Digital Sky Survey (SDSS) DR2 (~ 1/3 of total) images (5 Tb)  ~ 1 yr at 200 kb/s (ESO’s speed); catalogs (1.4 Tb)  ~ 3 months. On DVDs  ~ 1,000 of them. And analysis?? (similar size for MACHO, 2MASS etc …)  Ever increasing amount of data

3. July 13, 2004P. Padovani, The A-Star Puzzle3 R ~ 25.5, VLT/FORS2, t exp ~ 2.5 hrs (Szokoly et al. 2004)

4. July 13, 2004P. Padovani, The A-Star Puzzle4 Astronomical Data Explosion P. Quinn ~ 100 Gb/night

5. July 13, 2004P. Padovani, The A-Star Puzzle5 ESO/ST-ECF Science Archive Facility holdings 

6. July 13, 2004P. Padovani, The A-Star Puzzle6 The solution?  Data mining to increase observing efficiency  intelligent pre-selection  Statistical identification to diminish need for a spectrum  multi-wavelength, multi-parameter analysis  In-situ analysis to avoid download  Easy and smart access to all archives and data providers

7. July 13, 2004P. Padovani, The A-Star Puzzle7 The name: Virtual Observatory  An innovative, evolving system, which takes advantage of astronomical data explosion  It will allow users to interrogate multiple data centres in a seamless and transparent way and to utilize at best astronomical data  Data analysis tools and models will be made more accessible  It will allow new science by moving Astronomy beyond era of “classical” identification by combining all available information  Good communication  common language! Adoption and definition of VO standards and protocols within the International Virtual Observatory Alliance (IVOA: http://ivoa.net)  And it’s all happening now …

8. July 13, 2004P. Padovani, The A-Star Puzzle8 International Virtual Observatory Alliance Mission To facilitate the international coordination and collaboration necessary for the development and deployment of the tools, systems and organizational structures necessary to enable the international utilization of astronomical archives as an integrated and interoperating virtual observatory SVO

9. July 13, 2004P. Padovani, The A-Star Puzzle9 So what …?  The VO will make life much easier for all astronomers, even those not involved with colossal surveys, huge teams, and Tb of data! Web: all documents of the world inside your computer VO: all astronomical databases in the world inside your computer  Concrete example: Find all the high-resolution spectra of A-type stars available in all astronomical archives in a given wavelength range Tell me which ones are in raw or processed form Allow me to retrieve them If raw, give me access to the tools to reduce them on-the-fly Very time consuming, if at all possible, at present

10. July 13, 2004P. Padovani, The A-Star Puzzle10 Virtual Observatory in Europe  AVO Project started November 2001  Three-year, 5 M€, Phase A project, funded by the European Commission (FP5) and six organizations: ESO, ESA, AstroGrid, CNRS (CDS, TERAPIX), University Louis Pasteur, JBO  Manpower: ~ 17 FTEs/yr total, 50/50 EC and partners  Next step: EURO-VO, implementation phase (some EC funding secured, need more)  Visit us at http://www.euro-vo.org  Science Working Group established two years ago to provide scientific advice to AVO Project; implementation of selected science cases through demonstrations

11. July 13, 2004P. Padovani, The A-Star Puzzle11 The AVO Prototype  Evolution of Aladin (Centre de Donnés astronomiques de Strasbourg [CDS])  Downloadable Java application (http://www.euro-vo.org/twiki/bin/view/Avo/SwgDownload)  Extensible toolset with plug-ins which allows easy access to images, spectra, catalogues, with overlays, plotting facilities, and a cross-correlation utility  Still prototype but also research tool: first refereed, VO-based scientific paper “Discovery of optically faint obscured quasars with Virtual Observatory tools”, P. Padovani et al., A&A, in press (astro-ph/0406056) ST-ECF/ESO Press release May 28

12. July 13, 2004P. Padovani, The A-Star Puzzle12 A-star VO Cases 1.Establishing open cluster membership 2.Are chemically peculiar A-type stars more likely to be X-ray emitters than normal A-type stars? (Damiani et al., 2003)

13. July 13, 2004P. Padovani, The A-Star Puzzle13 Open Cluster Membership Pleiades: POSS II image

14. July 13, 2004P. Padovani, The A-Star Puzzle14 Loading catalogues parallax

15. July 13, 2004P. Padovani, The A-Star Puzzle15 Plotting Data: Parallax Histogram cluster parallax = 8.46±0.22 mas

16. July 13, 2004P. Padovani, The A-Star Puzzle16 Colour-magnitude diagram can correct for reddening by adding a new column ZAMS

17. July 13, 2004P. Padovani, The A-Star Puzzle17 Colour-magnitude diagram parallax

18. July 13, 2004P. Padovani, The A-Star Puzzle18 Open Cluster Membership Can be done now with existing tool, will be easier to do in the near future

19. July 13, 2004P. Padovani, The A-Star Puzzle19 Available archive data 2 clicks away from journal articles!

20. July 13, 2004P. Padovani, The A-Star Puzzle20 MAST data in detail  Cross-correlation of Sky2000 star catalogue with Multi- mission Archive at STScI (MAST; Optical/UV)  Out of 22,400 A-type stars: 754 have International Ultraviolet Explorer (IUE) data, for a total of ~ 10,000 observations 128 have non-IUE (FOS, GHRS, STIS, FUSE, EUVE, Copernicus, HUT, WUPPE, BEFS) data, for a total of 1,700 observations, ~ 60% of which are spectra How much else is available?

21. July 13, 2004P. Padovani, The A-Star Puzzle21 Peculiar A Stars in the X-rays Renson et al. (1991) catalog of 6684 chemically peculiar stars, 4736 of which A-type (equatorial projection)

22. July 13, 2004P. Padovani, The A-Star Puzzle22 HD catalog (blue; 272,150 sources) with A-type stars (yellow; 72,154) selected (equatorial projection) Peculiar A Stars in the X-rays: Comparison Sample

23. July 13, 2004P. Padovani, The A-Star Puzzle23 WGACAT of ROSAT PSPC observations, 88486 sources (equatorial projection) Peculiar A Stars in the X-rays

24. July 13, 2004P. Padovani, The A-Star Puzzle24 Chemically peculiar A- type stars in the X-rays  Cross-correlation of Renson et al. CP catalogue (A-type only) with WGACAT: 79/4736 matches = 1.7±0.6% (3  ; spurious matches subtracted). Magnetic only: 22/1433 = 1.5±0.7%  Cross-correlation of HD A-type stars with WGACAT: 392/72154 = 0.54±0.03%; correcting for CP star contamination (=10%; e.g., Monin et al. 2002)  ~ 0.4%  Cross-correlation of SAO A-type stars with WGACAT: 351/47230 = 0.7±0.1%; correcting for CP stars one gets ~ 0.6%  Chemically peculiar A-type stars are ~ 3 - 4 times more likely to be X-ray sources than normal A-type stars. Magnetic field appears not to play a role.

25. July 13, 2004P. Padovani, The A-Star Puzzle25 Chemically peculiar A-type stars in the radio band?  Cross-correlation of Renson et al. CP catalogue (A- type only) with (almost) all-sky radio catalogues down to ~ 1 mJy gives null results  Expected, given fluxes of few detected sources so far (  1 - 2 mJy, e.g., Drake et al. 1987)

26. July 13, 2004P. Padovani, The A-Star Puzzle26 Summary  The Virtual Observatory is happening, because it has to!  Handling and manipulating astronomical data and tools residing at various locations around the world will be made much easier than it is now  Everybody will benefit, including A-type star researchers!  Tools are available now to help you with your work

27. July 13, 2004P. Padovani, The A-Star Puzzle27 AVO prototype downloadable at http://www.euro-vo.org/twiki/bin/view/Avo/SwgDownload AVO Web Page

28. July 13, 2004P. Padovani, The A-Star Puzzle28 Astronomical Data on the Web

29. July 13, 2004P. Padovani, The A-Star Puzzle29 What’s Next for the European VO?  Finish the AVO Phase (last demo Jan. 2005)  We need to move towards EURO-VO:  Work with (not for) the data centres to increase interoperability [inter-archive tools] and promote high-quality, “science-ready” products; AVO needs these to be truly successful (see last demo)!  Make progress in turning ESO/ST-ECF archive “VO-compliant”  Funding situation not clear

30. July 13, 2004P. Padovani, The A-Star Puzzle30 The Future Grid+Net VO connecting all European astronomical data centres and providers

31. July 13, 2004P. Padovani, The A-Star Puzzle31 Persistent Data Standards User support IVOA link Distributed R&D VO Technologies for new projects and facilities 2005+

32. July 13, 2004P. Padovani, The A-Star Puzzle32 EURO-VO Resources - 4 Years Data Centre Alliance –UK, France, Germany, Italy, Netherlands, Spain, ESO, ESA [initially 15 Centres] –2 FTE per centre + 100 kEuro/yr upgrades Facility Centre –4 support scientists (registries, outreach, project support = ASTROVIRTEL II) Technology Centre –11 FTE development staff TOTAL: 15.5 Million Euro EC: 8 Million Euro

33. July 13, 2004P. Padovani, The A-Star Puzzle33 VO First Science!  First refereed, VO-based scientific paper: “Discovery of optically faint obscured quasars with Virtual Observatory tools”, P. Padovani et al., A&A, in press ESA/ESO Press release May 28