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VOYAGE Virtual Observatory, Yet Another Great Extension ?! should simulation data be included in a Virtual Observatory ? Alexander Knebe, Swinburne University.

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Presentation on theme: "VOYAGE Virtual Observatory, Yet Another Great Extension ?! should simulation data be included in a Virtual Observatory ? Alexander Knebe, Swinburne University."— Presentation transcript:

1 VOYAGE Virtual Observatory, Yet Another Great Extension ?! should simulation data be included in a Virtual Observatory ? Alexander Knebe, Swinburne University what ? why ? how ? …this is all biased towards cosmological n-body simulations

2 VOYAGE what are (cosmological) simulations anyway ? what ?

3 rotation curves of galaxies existence of Dark Matter  DM hierarchical structure formation nature of Dark Matter  CDM high redshift observations cosmology   CDM testing model using N-body simulations reveals… (Bahcall et al. 2001) VOYAGE what determines the model ? what ? model fixed ? observations observations

4 high resolution N-body simulations: observations: steep, cuspy density profiles hundreds of satellite galaxies small disk sizes mostly shallow density cores only a few satellites observed larger disk sizes  what ? VOYAGE what’s the problem ? breakdown of CDM paradigm on scales < 1 Mpc ?

5 VOYAGE time for a VOYAGE ? i.e., observed number of satellite galaxies orbiting in dark matter halo more data needed: from observers from simulators why ? correctly measured? correct models ? (Klypin et al. 1999)

6 VOYAGE why should VO be extended ?  simulations are time intensive  simulations contain 6D information: x(t), v(t)  cross-comparison of models possible  let’s pull the strings together: problems get solved only by exchange of ideas simulators need observers to gauge and improve models observers need simulators to calibrate observations why ?

7 VOYAGE simulations lead to observations ?! one ring encompasses it all ? simulated tidal stream of disrupted satellite galaxy milky way type dark matter halo observed stellar stream in own milky way halo why ? (Odenkirchen et al. 2003) (Gill et al. 2002)

8 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?

9 VOYAGE has the VOYAGE already begun ? all in non-compatible data formats, but the data is being used !  VIRGOSCDM,  CDM, OCDM,  CDM model particles Mpc/h box  “Hubble Volume”  CDM,  CDM model particles 3000 Mpc/h box  “COBE grid”68 (COBE-normalized) models (more than you can poke a stick at…) 64 3 particles 128 Mpc/h box  NEMO data archivecollection of links to data releases  plus some more by individual groups… how ?

10 VOYAGE can one feed on data alone ? how ?  MLAPMadaptive multi-grid code (Knebe et al. 2001)  GADGETtree-SPH code (Springel et al. 2000)  HYDRAAP 3 M code (Couchman et al. 1995)  hierarchical TreeCodeultra-fast (!?) tree code (Dehnen 2000)  PM codesimple PM code (Klypin 1995) (incl. analysis tools !) available codes: (mostly no analysis tools distributed !) most codes are proprietary products !

11 VOYAGE is there any consistency ? how ?  The Santa Barbara Cluster Comparison Project (Frenk et al. 1999) the oponents the oponents 6 Lagrangian codes(particle based) vs. 5 Eulerian codes (grid based) the outcome the outcome reassuring but also confusing the winner the winner ?

12 VOYAGE what’s the bottomline ? how ? add data add basic analysis (“simulated observations”) + add software:  codes  analysis tools

13 VOYAGE is it feasible ? hmm ?  requires great coordination  requires input from simulators  simulations outdate quickly...

14 VOYAGE Swinburne’s contribution !!! MLAPM is already publically available next MLAPM version will contain on-the-fly analysis we do have sophisticated visualisation tools for MLAPM data we do have high-resolution data (cf. Daisuke Kawata’s talk) we are more than happy to be part of this VOYAGE !

15 VOYAGE Swinburne’s contribution !!!  filament fragmentation  CDM  WDM z=5z=3 z=1z=0 (Knebe et al. 2003)

16 VOYAGE Swinburne’s contribution !!!  streams from disrupted satellite galaxies (Gill et al. 2002)

17 VOYAGE Virtual Observatory, Yet Another Great Extension ?! thank you for your attention and bon voyage... Alexander Knebe, Swinburne University

18 VOYAGE is there any consistency ? how ?  The Santa Barbara Cluster Comparison Project grid based codes particle based codes grid based codes temperature profileentropy profile (Frenk et al. 1999)

19 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?

20 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?

21 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?

22 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?

23 VOYAGE a little survey based on questionaire returned by 53 out of 106, Astrophysical Supercomputing Using Particle Simulations, IAU Symposium 208, Tokyo, July 2001 (P. Teuben, astro-ph/ ) how ?


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