Simulating Proto-clusters utilizing the Austrian Grid

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Michaela Lechner Eelco van Kampen Daniel Clarke Simon Ostermann Manchester, May 2007. Simulating Proto-clusters utilizing the Austrian Grid. Institute of Astro- and Particle Physics Distributed and Parallel Systems Group Institute for Computer Science. - PowerPoint PPT Presentation

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  • Simulating Proto-clusters utilizing the Austrian Grid

    Michaela Lechner Eelco van KampenDaniel Clarke

    Simon Ostermann

    Manchester, May 2007

    Institute of Astro- and Particle Physics

    Distributed and Parallel Systems GroupInstitute for Computer Science

  • Protocluster Science is Sub-mm ScienceSub-mm:200m - 1mm Millimeter: 1mm - 10mmSub-mm needed forHigh-z galaxy formationHigh-z clusters (structure formation?)Technology just starting to mature, breakthrough inevitable.JCMT citation rate rivals HST!At 850m, a galaxy has same flux density from z = 1 - 10

  • James Clerke Maxwell TelescopeLargest existing sub-millimeter one dish telescope in the world (diameter of 15m)The JCMT is used to study our Solar System, interstellar dust and gas, and distant galaxies. Situated close to the summit of Mauna Kea, Hawaii, at an altitude of 4092m (high & dry). SCUBA: The Submillimetre Common-User Bolometer Array

  • SHADES: SCUBA Half Degree Extragalactic Survey Lockman Hole East Subaru/XMM-Newton Deep FieldIt is not yet possible to measure the clustering properties of sub-mm sources. Redshift determination is currently in progress. (radio correlation)

  • More sub-mm in the FutureALMA: Atacama Large Millimeter Array

    Herschel Space ObservatorySCUBA-2 (starting January 2008)HSOALMAcomplete: 2012operating: 2009launched: 2007

  • SCUBA-2 on JCMTlarge 8 x 8 arcmin field-of-viewSimultaneous imaging at 450 and 850mFully-sampled images of the sky in
  • Simulating ObservationsIngredients for a Semi-numerical Galaxy Formation:

    Cosmological model (standard)Halo formation and merger historyGas dynamics and radiative coolingStar formation and stellar feedbackStellar population synthesisAccurate Dust modelCDM model of van Kampen, Rimes & Peacock (2004)

  • Simulating Observationsonly oncevery fastGRASILInitial data set currently created on HPC ClusterIngredients for a Semi-numerical Galaxy Formation:

    Cosmological model (standard)Halo formation and merger historyGas dynamics and radiative coolingStar formation and stellar feedbackStellar population synthesisAccurate Dust model

  • The Dust Model: GRASILGraphite and Silicone: principal contributors to galactic dustConsiders the physical effects of graphite, silicate and PAH particles on a galaxys SEDby Laura Silva (Gian Luigi Granato) 1999, FORTRAN 95Calculates the complex line integral between volume elements as a photon travels through the galaxy. Computationally intensive! Small code, small data filesOutputfiles: SED Data (1-2 kB)Problem ideally suited for Grid Computing!BulgeMolecular cloudDiskDiffuse ISM, Free stars and CirrusEquatorial planeSmall code, small data filesOutputfiles: SED Data (1-2 kB)All galaxies independent from each other

  • Simulating ObservationsCreation of Galaxy Formation model predictions:Comparing predictions with future observationsCurrent lightcone with 60 timeslices ~ 20.000 galaxies -> 1 million galaxiesPredicting whole lightcone -> usable for all telescopes and wavelength regimesProtoclusters:Only interested in part of the lightcone (relevant timeslices)

  • Looking into the past

    P. Heinmki, I. Suhhonenko, E. Saar, M. Einasto, J. Einasto, and H. VirtanenSPITZERHerschelALMASCUBA 2

  • including noise and observational effects

    With a survey field of 100 square degrees, it seems statistically likely, based on dark matter simulations that both an over density region and blank field will be observed early in the survey.. Mock SCUBA-2 survey: super-SHADES with 100 square degrees

    This is what we currently have

  • SCUBA-2 legacy surveys2 years5 years

  • Simulating Observations

  • Porting to the Austrian GridSplitting one big parameter file into small parameter files for each galaxy in generation of initial data set in GRASILCompiling GRASIL in 3 different flavors:generic 32 bitAMD64Itanium 2Porting to the Austrian Grid reduces computational time per galaxy to approximately 4.2 seconds. (Lechner et al. 2007)

  • ASKALON WorkflowSimple workflow: Input Data Streamer ActivityParallel LoopCollector ActivityGRASIL Activity deployed on several Grid-sites, embarrassingly parallel.

  • ASKALON WorkflowPreparation of data: Ruby script creating jobset-tarballs (future ASKALON will do it automatically)less overheadmore balancing(list of galaxies is not continuous)Auto deployment of GRASILPerformance monitoring/predictions

  • Increasing code efficiencyCalculating the correlation matrix of the input parameters suggests that the following parameters are co-correlated with execution time:Host machine Radius of the Disk componentCold gas massCold gas metallicity Total stellar massBulge density

    Testrun with 25000 Galaxies on different Grid sitesFor each host type, there is a clear clustering of effective execution time.

  • ASKALONLocal Installation or as a Java Webservice

  • Autodeployment in ASKALON

  • Blank Field

  • Inserted proto-cluster @ z=2.5A proto-cluster at z2.5 significantly boosts the number of visible 850 m sources, compared to a field-only map. Both maps are half a square degree in size with a resolution according to the JCMT beam.

  • Matching sub-mm galaxy number countsMock with no (proto)-clusterMock with 1 (proto-)clusterMock with 2 (proto-)clustersUnderlying figure from Coppin et al. (2006)

  • Finding proto-clusters in the SCUBA-2 and Herschel surveysNumber overdensity of sub-mm sources for a field containing a rich proto-cluster increases with the flux cut.

  • Conclusions ISub-mm observations is probably one of the most important wavebands in modern cosmologyWith the next generation of Sub-mm surveys it seems likely that observations of over density regions will become commonAccurate simulations of proto-clusters will help us to understand the physics behind cluster and galaxy formation.For simulations to keep pace with detector technology developments, new computing techniques need to be adapted.Urgency: Comparison with observations soon!Extreme case of parallelization, huge amount of calculation power needed.Input for Grid Middleware (ASKALON) improvement

  • Conclusions IIClustering is detected in SHADES, but with large uncertaintiesRedshifts or large surveys are needed to improve upon this: the SCUBA-2 and/or Herschel legacy survey(s)Bright sub-mm sources are mostly associated with high-density regions (proto-clusters and the like)the contribution of (proto)-clusters to sub-mm source counts shallow (> 12 mJy) surveys are sufficient to find high-z (proto-)clusters

  • Thank you!

    Our Scientific Topic is Dust Emission of young galaxies at high redshifts. - that means galaxies far away in the pastbetween a few hundred micrometres and a millimetre. I

    Synchrotron -- relativistic electrons in SNR. Free-free (Bremstrahlung) -- ionized gas. Inverse compton scattering -- Sunyaev-Zel'dovich (SZ) clusters

    Detailed analysisclustering, luminosity, number counts (2 papers already out, 2 in progress (e.g. estimate distances of sources))Herschel European Mission (ESA) Software Engenieering for Herschel aslo done in Viennanext generation instrument

    a 1000 times faster then SCUBA, really new technology, a big step.

    --> bigger data sets, more sensitive

    Resolution still determined by telescope

    see JCMT and prototypeCreating initial Data Set

    Only Dust modelling done with GRASIL

    cosmological model and halo formation and merger history: done only once

    other 3 points very fast

    first 5 points done on the HPC clusterCreating Initial Data Set

    Only Dust modelling done with GRASIL

    cosmological model and halo formation and merger history: done only once

    other 3 points very fast

    first 5 points done on the HPC clusterComputation time depends on physical properties.

    Looking back along the line of sightEach activity stands for 1 binary or wrapper, that can be deployed on several gridsites.ASKALON knows the locations of the deploymentThe Input Data Streamer Activity provides the Data for the Grasil Activity

    (Streamer and Collectur currently only on altix1)

    Use current Performance Monitoring and Predictionsas they are already implimentted in ASKALON, and also interpret the timestamps we save for each galaxy.Really in the middle of working of this fascinating project in the last 2 weeks ASKALON improved a lot, and we had to readapt our workflow implementation a little bit.

    So instead of a really big run I wanted to present here, I show you the numbers of the very last runs, that are mainly here now for us to estimate the runtime of one of the 60 timeslices of the lightcone for one model.

    We also ran into quotaproblems on the zIDGrid Sites, as at the moment we dont only collect the actual result we need, but all the files.

    These numbers are not at all balanced well. The thing I should really mention here as a result is actually the good working close coorperation with the DPS Group. More or less everybody who is working on ASKALON did already something for this project. And I want to say thank you to all those people.