1. Astro-DISC: Astronomy and cosmology applications of distributed super computing

2. Purpose A toolkit for massive astronomical and cosmological computations on large clusters, which will include software tools and algorithmic methods.

3. Universe The visible universe is large: 28 billion light years 10 million galaxy superclusters 25 billion galaxy clusters 350 billion large galaxies 7 trillion dwarf galaxies 30 sextillion (3 ∙ 10 22 ) stars

4. Data sets Sky surveys: Billions of objects (stars, galaxies, …) Multiple images of the same object Simulations: Billions of objects Multiple runs Multiple time points Sloan Digital Sky Survey (2000–2008): 230 million objects, 50 TByte Pan-STARRS (started in 2008): Half-order of magnitude larger than Sloan Large Synoptic Survey Telescope (2016): Order of magnitude larger than Sloan McWilliams Center at CMU: Black holes and dark matter, 15B particles, 14 TByte / run LANL Coyote universe: 1B particles, 1 TByte / run, 30 runs Many other projects

5. Data sets The sizes of modern survey and simulation datasets are between 1 and 100 billion objects. Their analysis requires distributed computing. Even larger sets are coming soon.

6. Astronomers vs. computer scientists

7. DISC Cloud cluster at Carnegie Mellon Each node: Eight 2.83GHz cores Four 1TB disks 16 GByte memory Sixty-four nodes 10GBit / second network

8. 40% 60% observed object Specific problems Friends of Friends: Identification of galaxy clusters Correlation functions: Analyzing distribution of distances between galaxies Spatial matching: Identification of observed objects in the catalog catalog distance

9. More problems Particle history: Tracking the history of particles in astrophysics simulations Quasar detection: Identifying quasars based on the five passband fluxes

10. General-purpose astronomy toolkit: Massive spatial indices of celestial objects, integrated with distributed algorithms Future work Distributed computation for other standard astronomy problems: Density distribution, photometric calibration, asteroid detection,...