Two possible ways to add theory to the AVO/eAA Case study from Swinburne Astronomy Online

1. Adding Theory to the Virtual ObservatorySarah Maddison Centre for Astrophysics & SupercomputingSwinburne UniversityOutline • Two possible ways to add theory to the AVO/eAA • Case study from Swinburne Astronomy Online ANITA Workshop, January 2003

2. Two Ways to Add Theory to AVO • Addition of theoretical astrophysics to AVO could be done in many ways, two of which include: • (1) database of codes; and • (2) database of theoretical models & synthetic obs ANITA Workshop, January 2003

3. (1) Database of codes: There are currently a variety of freely available codes online and ready to download, including: • ZEUS:grid based code for astrophysical radiation MHD available through the NCSA. • Codes available include: ZEUS2D,ZEUS3D,ZEUSMP (explicit Eulerian grid codes)TITAN (1D implicit adaptive mesh code)KRONOS (3D PPM + PM hydro grid code) 4D2 (SGI visualisation tool for 3D data) • Code freely available & bugs reported to NCSA. Comes with method paper describing algorithm, a users guide, plus test suite. Asked to register to track software use. • Written by Jim Stone (after Mike Norman)http://zeus.ncsa.uiuc.edu:8080/lca_codes_docs.html ANITA Workshop, January 2003

4. (1) Database of codes: • There are currently a variety of freely available codes online and ready to download, including: • HYDRA: Consortium which provides public-domain software for N-body hydro. Interested in galaxy & cluster formation. • Software available:hydra (adaptive PP-PM + SPH code)ap3m(adaptive PP-PM code, older but faster than hydra) • Code freely available & bugs reported. Contains installation file, algorithm papers, cosmological IC & BC generator. Also asked to register. • Written by Hugh Couchman, Frazer Pearce & Peter Thomas.http://hydra.mcmaster.ca/hydra/index.html ANITA Workshop, January 2003

5. (1) Database of codes: • There are currently a variety of freely available codes online and ready to download, including: • GADGET: galaxies with dark matter and gas interact • N-body + SPH code for cosmological simulations, includes star formation & feedback. Serial & MPI parallel versions. • Code is free software distributed under the GNU General Public License. Comes with code paper, users guide and ReadMe files. Asked to register to track software use. • Written by Volker Springel & extended by Naoki Yoshida http://www.mpa-garching.mpg.de/gadget/ ANITA Workshop, January 2003

6. (1) Database of codes: • There are currently a variety of freely available codes online and ready to download, including: • MLAPM: adaptive grid code for cosmological sims; Knebehttp://astronomy.swin.edu.au/staff/aknebe/MLAPM/ • NMSU Particle Code: PM code; Klypin & Hotzman http://astro.NMSU.Edu/~aklypin/pm.htm • N-Body Shop: variety of N-body tools; U.Wash HPCC http://www-hpcc.astro.washington.edu/tools/ • SWIFT: solar system integration software for calculating planetary orbits, written by Hal Levison & Martin Duncanhttp://www.boulder.swri.edu/~hal/swift.html • CLOUDY: plasma simulation code for interpreting spectroscopic data, written by Gary Ferlandhttp://nimbus.pa.uky.edu/cloudy/ ANITA Workshop, January 2003

7. (1) Database of codes: • All these downloadable codes available at individual sites could easily be incorporated in the VO (with VO acting as a library). • One step further: run codes over the web or via the VO • advantage: could compare different types of codes on the same problem (e.g. grid versus particle codes) • problem: whose computer parallel codes run on and who stores the data • problem: not all codes publicly available… would be limited by number of codes made available • problem: who would maintain them?…authors like now or could be use at own risk (just like observational data!!) • limited more by participation... ANITA Workshop, January 2003

8. (2) Database of models & synthetic obs: • run your codes with a range of parameters and make the results publicly available (e.g. stellar evolution codes, N-body codes, hydro codes, radiative transfer codes etc...) • Virgo Consortium: formation of galaxies, clusters, large scale structure, and evolution of IGM.Projects include: • The Hubble Volume: study cluster, filament & void formation; snapshot data, lightcones, cluster catalogue • The VIRGO project: cosmological N-body simulation data archive; snapshots at various z for various cosmologies • http://www.MPA-Garching.MPG.DE/Virgo/data_download.html • GRETA - European radiative transfer group, some models onlinehttp://www.obs-nice.fr/stee/transfert/transfert.html ANITA Workshop, January 2003

9. (2) Database of models & synthetic obs: • run your codes with a range of parameters and make the results publicly available (e.g. stellar evolution codes, N-body codes, hydro codes, radiative transfer codes etc...) • advantage: can make synthetic data to compare with your observations, including resolution & seeing etc. • problem: huge job of working out what parameters to search and how to tabulate/store the data, but the same problems exist with observational data… • limited only by time (=money) and imagination! ANITA Workshop, January 2003

10. A Case Study • Swinburne Astronomy Online includes a major project subject on Computational Astrophysics, allowing students with minimal computing experience to run numerical experiments in computational astrophysics & gain a deeper understanding of complex astronomical concepts. • Contains 6 modules: • stellar orbits • pulsar population synthesis • galactic dynamics • galaxy interactions • solar system dynamics • stellar evolution For details, see http://astronomy.swin.edu.au/sao/het617/ ANITA Workshop, January 2003

11. Stellar Orbits: Simple N=2 or 3 codes to experiment with orbits; written inhouse by SAO Group • Pulsar Population Synthesis:Creates synthetic pulsar population & observes with a virtual telescope (,beamwidth, bandwidth, channels, integration..); written inhouse by Pulsar Group • How it works: ANITA Workshop, January 2003

12. Galaxy Interactions:3D N-body code with two 3 component galaxy models; inhouse N-body code plus GalactICs for initial conditions • How it works: • Galactic Dynamics:3D N-body code with a 3 component galaxy model; written inhouse by Cosmology Group ANITA Workshop, January 2003

13. Stellar Evolution:access topre-computed stellar evolution data for various Mstar and z; code & data by Lattaznio • How it works: • Solar System Dynamics:3D N-body code SWIFT to model Np planets & NTP test particles 1. Setup the Npplanets (given e, a, i, M) 2. Setup the NTPtest particles (given range of e, a, i) 3. Run integrator and evolve system ANITA Workshop, January 2003

14. The mechanics: • Students log on to specific module in web server • PHP scripting allows various input parameters & runs job • Job submitted to Swinburne supercomputer (SAO nodes) • Pseudo queuing system setup • Results/data/plots returned to student data directory; currently just 3 models stored; students emailed at completion of long job • The results: • Tons of beta testing required! • Loads of documentation required • Loads of helpdesk support  But students did some really great real science projects! ANITA Workshop, January 2003

15. Summary • There is no reason why the VO could not include a theory component (may need to change name…) • Exactly how this would be done depends on what user want (access to codes or access to data - what codes & what data) • An educational test case indicates that good science can be done using either model (database of results, or interface to a code) • Next step: decide what users want! ANITA Workshop, January 2003