Maurizio Salaris & Santi Cassisi & Fabio Pasian ARI – Liverpool John Moores University, UK

1. In collaboration with: Pietrinferni F. Castelli D. Cordier M. Castellani P. Manzato R. Smareglia G. Taffoni C. Vuerli BaSTI@VObs & GRID a Bag of Stellar Tracks & Isochrones …and… much more! Maurizio Salaris & Santi Cassisi & Fabio Pasian ARI – Liverpool John Moores University, UK INAF – Collurania Astronomical Observatory, I INAF – Trieste Astronomical Observatory, I S. Percival

2. Why…,? Stellar evolution model and isochrone archives are a fondamental working tool in modern astrophysics. Their use ranges from the study of single stellar objects, to Galactic and extragalactic stellar systems, in the near universe and at high redshift. • Improvements in the physical inputs • Homogeneity • Coverage of the parameter space • User friendly

3. Input physics • Equation of State: FreeEos by A. Irwin (2005) • Radiative opacity: high-T OPAL (Rogers et al. 2000) - low-T Alexander & Ferguson (1994) + Ferguson et al. (2005) • Conductive opacity: Potekhin (1999) • Nuclear cross sections: NACRE (Angulo et al. 1999) + updates (Kunz et al. 2000, Formicola et al. 2003 + …) The most updated library of stellar evolution models currently available!!!

4. The coverage • 11 metallicities: from Very Metal-poor Stars to Very metal-rich ones • Heavy elements mixture: scaled solar & α-enhanced • Helium abundance: Ypr=0.245 - Y/Z~1.4 • Core convection: canonical & overshooting • Mass loss: Reimers’ law with =0.2 and 0.4 • Extremely fine mass grid for all evolutionary stages • From the Pre-Main Sequence to the end of the Asymptotic Giant Branch or C-ignition • Updated Color – Teff transformations + BC scale

5. Why, What, .... ? • Evolutionary tracks • Isochrones • Luminosity Functions • Synthetic Colour – Magnitude Diagrams • Tables with relevant data

6. Evolutionary tracks & isochrones: some examples

7. Horizontal Branch stellar models: some examples RR Lyrae instability strip Accurate sampling of the different evolutionary phases A reliable tool for population synthesis analysis A fundamental ingredient for investigating the properties of different types of pulsating stars

8. Synthetic Colour-Magnitude diagrams ~90,000 objects SFR typical of the solar neighbourhood Salpeter IMF 1 photometric error of 0.03 mag 20% unresolved binaries an example! we can account for a spread in the AMR, photometric errors, depth effects, interstellar extinction and unresolved binaries It provides information about the number and period distribution of various types of radially pulsating stars

9. NGC2420: • (mM)0=11.90 mag • E(BV)=0.06 • [Fe/H]=0.44 • solid – overshooting 3.2Gyr • dashed – canonical 2Gyr Theory  Observations: some scientific cases

10. Determination of Star Formation Histories

11. NHB –number of HB stars NRGB–number of RGB stars brighter than the HB The Horizontal Branch: The R parameter The mean GC He abundance is Y=0.250±0.006 Fully consistent with the primordial He abundance obtained by CMB observations coupled to primordial nucleosynthesis calculations

12. Initial-Final mass relation

13. Future developments • more models… • more chemical compositions… • more photometric filters… • integrated colours, mass-to-light-ratios • theoretical high resolution Spectral Energy Distributions…

14. Integrated spectra • We are at present working intensively (large part of the work is completed) on computing theoretical integrated spectra (at both low- and high resolution), integrated colours, mass-to-light ratios, for studies of extragalactic stellar populations Low resolution theoretical spectra of a typical Galactic globular cluster and an old open cluster

15. Integrated properties of extragalactic Stellar Systems

16. Why, What, Where ? A Bag of Stellar Tracks and Isochrones

18. A WEB interface allows the user to compute Evolutionary Tracks/Isochrones/Luminosity Functions/Synthetic CMDs

20. Some numbers related to the BaSTI “traffic”(last update 8 May 2007) • Visits (since Feb. 2004): • Total – about 6000 • Average per day – 9 • Average visit length – 5 min • Page views (since Feb. 2004): • Total – about 13000 • Average per day – 19 • Average per visit – 2.1 Summary of last year’s visits and page views The refereed papers introducing BaSTI have collected 138 citations in 19 months

21. Standards… Query language Data access layer Semantics Data models The BaSTI archive @ A pilot project for stellar astrophysics • To make the archive VO compliant • Re-building the database to allow ADQL access

22. Connection with three WPs WP3 – integration of DBs WP4 – theory within VO WP5 – connection with grids The BaSTI archive @ Part of the EU/FP6 funded VO-DCA project The state-of-the-art: • Will participate in definition of VO Data Model for theory • Will test integration of VO-compliant DB with EGEE

23. State-of-the-art: Our evolutionary code is now efficiently running within LINUX platform and we start the preliminary tests needed before a massive use of the Grid infrastructure. Mid-term projects: We plan to compute in the next few months an extended set of stellar models for chemical compositions and masses not yet included in the BaSTI archive. We’ll also compute a large set of integrated spectra for stellar populations with complex Star Formation Histories Long-term project: We wish to allow an “on-line” access to our evolutionary code so that users can compute their own evolutionary models: the computational work should be performed within a Grid infrastructure Basti & GRID • Finalising the ‘gridification’ of the code to allow the calculation of new models using the Grid infrastructure

24. EGEE Added Values • CPU power: • E-computing lab • Production burst • Efficient CPU usage/sharing • Data storing/sharing: • Distributed data for distributed users • Replica and security • Common interface to software and data FRANEC simulations are highly computing demanding and produce a huge amount of data.

25. Proposed Activity • Run simulations of the FRANEC code on the Grid • Manage Job submission from portal; • Store data on Grid environment; • Share data to Virtual Observatory Community • Interoperability use case(?)

26. Proposed Activity • To allow users to run FRANEC simulation SW we need to create some specific services on EGEE common environment; • They must be used to run both one or more stellar population runs; • They are modular and easy to integrate with new code implementations: when some upgrade is needed.

27. Expected implementation

28. Why EGEE EGEE infrastructure is stable and efficent; Need to use job management + data management + metadata management services Services are not too complicated to integrate;