Simulating Proto-clusters utilizing the Austrian Grid Michaela Lechner Eelco van Kampen Eelco van...

27
Simulating Proto-clusters Simulating Proto-clusters utilizing the Austrian Grid utilizing the Austrian Grid Michaela Lechner Michaela Lechner Eelco van Kampen Eelco van Kampen Daniel Clarke Daniel Clarke Simon Ostermann Simon Ostermann Manchester, May Manchester, May 2007 2007 Institute of Astro- and Institute of Astro- and Particle Physics Particle Physics Distributed and Parallel Distributed and Parallel Systems Group Systems Group Institute for Computer Institute for Computer Science Science

Transcript of Simulating Proto-clusters utilizing the Austrian Grid Michaela Lechner Eelco van Kampen Eelco van...

  • Slide 1

Simulating Proto-clusters utilizing the Austrian Grid Michaela Lechner Eelco van Kampen Eelco van Kampen Daniel Clarke Simon Ostermann Manchester, May 2007 Institute of Astro- and Particle Physics Distributed and Parallel Systems Group Institute for Computer Science Slide 2 Protocluster Science is Sub-mm Science Sub-mm: 200m - 1mm Millimeter: 1mm - 10mm Sub-mm needed for High-z galaxy formation High-z clusters (structure formation?) Technology just starting to mature, breakthrough inevitable. JCMT citation rate rivals HST! At 850 m, a galaxy has same flux density from z = 1 - 10 Slide 3 James Clerke Maxwell Telescope Largest 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 JCMT Slide 4 SHADES: SCUBA Half Degree Extragalactic Survey Lockman Hole East Subaru/XMM-Newton Deep Field Lockman Hole East Subaru/XMM-Newton Deep Field It is not yet possible to measure the clustering properties of sub-mm sources. Redshift determination is currently in progress. (radio correlation) Slide 5 More sub-mm in the Future ALMA: Atacama Large Millimeter Array Herschel Space Observatory SCUBA-2 (starting January 2008) HSO ALMA complete: 2012 operating: 2009 launched: 2007 Slide 6 SCUBA-2 on JCMT large 8 x 8 arcmin field-of-view Simultaneous imaging at 450 and 850m Fully-sampled images of the sky in Simulating Observations Creation of Galaxy Formation model predictions: Comparing predictions with future observations Current lightcone with 60 timeslices ~ 20.000 galaxies -> 1 million galaxies Predicting whole lightcone -> usable for all telescopes and wavelength regimes Protoclusters: Only interested in part of the lightcone (relevant timeslices) Slide 11 Looking into the past P. Heinmki, I. Suhhonenko, E. Saar, M. Einasto, J. Einasto, and H. Virtanen Time SPITZER Herschel ALMA SCUBA 2 Slide 12 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 Slide 13 SCUBA-2 legacy surveys 2 years 5 years Slide 14 Simulating Observations Slide 15 Porting to the Austrian Grid Splitting one big parameter file into small parameter files for each galaxy in generation of initial data set in GRASIL Compiling GRASIL in 3 different flavors: generic 32 bit AMD64 Itanium 2 Porting to the Austrian Grid reduces computational time per galaxy to approximately 4.2 seconds. (Lechner et al. 2007) Slide 16 ASKALON Workflow Simple workflow: Input Data Streamer Activity Parallel Loop Collector Activity GRASIL Activity deployed on several Grid-sites, embarrassingly parallel. Slide 17 ASKALON Workflow Preparation of data: Ruby script creating jobset- tarballs (future ASKALON will do it automatically) less overhead more balancing (list of galaxies is not continuous) Auto deployment of GRASIL Performance monitoring/predictions Slide 18 Increasing code efficiency Calculating the correlation matrix of the input parameters suggests that the following parameters are co-correlated with execution time: Host machine Radius of the Disk component Cold gas mass Cold gas metallicity Total stellar mass Bulge density Testrun with 25000 Galaxies on different Grid sites For each host type, there is a clear clustering of effective execution time. Slide 19 ASKALON Local Installation or as a Java Webservice Slide 20 Autodeployment in ASKALON Slide 21 Blank Field Slide 22 Inserted proto-cluster @ z=2.5 A 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. Slide 23 Matching sub-mm galaxy number counts Mock with no (proto)-cluster Mock with 1 (proto-)cluster Mock with 2 (proto-)clusters Underlying figure from Coppin et al. (2006) Slide 24 Finding proto-clusters in the SCUBA-2 and Herschel surveys Number overdensity of sub-mm sources for a field containing a rich proto-cluster increases with the flux cut. Slide 25 Conclusions I Sub-mm observations is probably one of the most important wavebands in modern cosmology With the next generation of Sub-mm surveys it seems likely that observations of over density regions will become common Accurate 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 Slide 26 Conclusions II Clustering is detected in SHADES, but with large uncertainties Redshifts 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 shallow (> 12 mJy) surveys are sufficient to find high-z (proto-)clusters Slide 27 Thank you!