Post-Newtonian Dynamics Post-Newtonian Dynamics And the future: And the future: Billion bodies and Exascale? Billion bodies and Exascale? SFB881 Rainer Spurzem*, Peter Berczik, Silk Road T eam Rainer Spurzem*, Peter Berczik, Silk Road T eam (here: Long Wang, Paulina Assmann, Yohai Meiron) (here: Long Wang, Paulina Assmann, Yohai Meiron) Key Laboratory for Computational Astrophysics, Key Laboratory for Computational Astrophysics, National Astronomical Observatories (NAOC), Chinese Academy of Sciences National Astronomical Observatories (NAOC), Chinese Academy of Sciences Kavli Institute for Astronomy and Astrophysics (KIAA), Peking University Kavli Institute for Astronomy and Astrophysics (KIAA), Peking University Astronomisches Rechen-Inst., ZAH, Univ. of Heidelberg, Germany Astronomisches Rechen-Inst., ZAH, Univ. of Heidelberg, Germany spurzem@nao.cas.cn , http://silkroad.bao.ac.cn *Special State Foreign Expert in Thousand People's Plan in China Lund 2015
● Software/Hardware/Large N-Body ● Post-Newtonian and Grav. Waves ● Mixed Notes / Summary
Pictures from: Chinese President Xi Jinping http://www.chinatourselect.com/ welcomes “Foreign Experts” http://silkroad.bao.ac.cn National Astronomical Observatory of Chinese Academy of Sciences, Beijing China Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, China Fesenkov Astrophysical Institute, Space Institute, Almaty, Kazakhstan Institute of Space Technology, Islamabad, Pakistan (NEW) Main Astronomical Observatory of Ukrainian Academy of Sciences, Kiev, Ukraine Astronomisches Rechen-Institut,Zentrum f. Astronomie (ZAH) and Computer Engineering and Architecture (ZITI), Univ. Of Heidelberg, Germany Max-Planck Institute for Astrophysics (MPA), Garching/Munich, Germany
“Moore's” Law for Direct N-Body ● Wang, Aarseth, Sp 15 GRAPE/GPU Clusters 10**6 ● Heggie et al. 15 ● Makino, Baumg. Merritt..., ● Baumgardt, Heggie, Hut GRAPE Baumgardt, Makino Vector Computers 2010 by D.C. Heggie Via www.maths.ed.ac.uk added new cits. Spurzem August 22, 2002 4
NBODY6++/GPU Wang, Spurzem, Aarseth, et al. 2015 (GPU's)
Wang, Spurzem, Aarseth, Berczik, Nitadori, 2015, MNRAS Slide of: Long Wang
Wang et al. 2015a Huang et al. 2015
NBODY6++GPU Huang, Berczik, Spurzem, acc. for publ. 2015.
Parallel TREE GPU gravity Jun Makino (pC++): TREE+GRAPE/GPU code N GR BONSAI Full GPU Gaburov et al. Makino, PASJ, 56, 521 (2004) Makino, PASJ, 43, 621 (1991) Fukushige, Makino & Kawai, PASJ, 57, 1009 (2005) One interaction list is shared among Inter. list on host ~N NGR particles! Inter. list length -> short… Inter. list on host ~N/NGR Inter. list length -> larger…
BONSAI Huang, Berczik, Spurzem, acc. for publ. 2015
IWR April 2014
64 21 2013: Click to edit the outline text format ● Second Outline Level – Third Outline Level ● Fourth Outline Level – Fifth Outline Level ● Sixth Outline Level ● • Seventh Outline LevelClick to edit Master text styles – Second level • Third level – Fourth level
Our Green Grid: GPU Clusters used: 老虎 Beijing (NAOC/CAS and Silk Road Project (NAOC/CAS and Silk Road Project ) 85 Nodes, 170 Tesla C1060, 59 (64) Kepler K20 Golowood cluster, Main Astron. Observatory, Kiev, Ukraine Kepler cluster Heidelberg, Germany (12x Kepler GPU) Hydra Cluster MPA Garching (400 Kepler K20) Heidelberg Germany Milkyway Jülich KIAA / NAOC Beijing 老虎 老虎 NAOC Beijing NAOC Beijing IWR April 2014 09/17/15
Nr. 1 Supercomputer from China: 33 Pflop/s Linpack Guangzhou National Supercomputing Center http://www.top500.org 32000 Intel Xeon 12 core, 48000 Intel Phi Accelerators 57 Core
IWR April 2014
IWR April 2014
● Software/Hardware/Large N-Body ● Post-Newtonian and Grav. Waves ● Mixed Notes / Summary Lund 2015
Post-Newtonian Dynamics Post-Newtonian Dynamics Method A: use geodetic equations, harmonic gauge, directly obtain eqs. of motion (Blanchet et al.) Method B: Hamiltonian approach using ADM gauge (Schaefer et al.) A and B equivalent till PN2.5 (1/c**5), higher order gauge functions appear. Perihel shift ... higher order... Grav. Radiation IWR April 2014
Post-Newtonian Dynamics Post-Newtonian Dynamics Spin-Orbit Interaction S / Spin-Spin SS Faye, Blanchet, Buonanno 2006 IWR April 2014
Post-Newtonian Dynamics Post-Newtonian Dynamics Brem, Amaro-Seoane, Spurzem, MNRAS 2013 Include Spin-Orbit Spin-Spin PN3, PN3.5 Spin Dynamics By Patrick Brem (Diploma Thesis Univ. Heidelberg) 1PN 2PN + 1.5PN SO 3PN + 2.5PN SO 2.5PN + 2PN SS 3.5PN
Post- Post- Newtonian Newtonian Dynamics Dynamics Gravitational Gravitational Wave Wave Templates Templates Handle spin-orbit and spin-spin coupling (P.Brem, R. Spurzem, IWR April 2014 Univ. Heidelberg)
Rezzolla Final Spin Formula Brem, Amaro-SeoaneS, Spurzem, MNRAS 2013 IWR April 2014
Slide by Paulina IWR April 2014
MNRAS 2010 MNRAS 2010 MNRAS 2011
Downing et al. 2011
VIRGO Detector in Cascina near Pisa, Italy IWR April 2014
IWR April 2014
From Pitkin et al., Living Reviews 14 (2011) 5, Grav. Wave Detection... IWR April 2014
● Software/Hardware/Large N-Body ● Post-Newtonian and Grav. Waves ● Mixed Notes / Summary Lund 2015
DRAGON Simulation One million stars direct simulation, http://silkroad.bao.ac.cn/dragon/ biggest and most realistic direct N-Body simulation of globular star clusters. With stellar mass function, single and binary stellar evolution, regularization of close encounters, tidal field (NBODY6++GPU). (NAOC/Silk Road/MPA collaboration). Wang, Spurzem, Aarseth, Naab et al. MNRAS, 2015a Wang, Spurzem, Aarsteh Naab, et al. to be subm. MNRAS 2015b IWR April 2014
Million Body Simulation NBODY6++GPU (Wang et al. Paper II in prep.) DRAGON SPACE TELESCOPE Simulation, 6 Gyr IWR April 2014
Direct Simulation (Poster Long Wang) Direct Simulation (Poster Long Wang) NBODY6++GPU 1 Million Bodies NBODY6++GPU 1 Million Bodies Wang, Spurzem, Aarseth, Berczik, Nitadori, Kouwenhoven, Naab 2015a subm. MNRAS, Wang et al. 2015b, in prep. Used RZG Garching hydra GPU cluster (400 Kepler GPUs)
...confirmed by N-Body Model of Khalisi, Amaro-Seoane & Spurzem 2007 μ = m2/m1 (Two Component Model) Also Spitzer Mass Segregation Instability Confirmed... IWR April 2014 09/17/15
Pang et al. 2015, in press RAA Lund 2015
ApJS 2015 Lund 2015
Bialas et al. 2015, A&A Lund 2015
The future of NBODY6+ +GPU ● Improve Multi-Core and Many Core Hybrid currently: MPI/Open MP+AVX/CUDA (OpenCL) ● Improvement of Communication ● More overlapping operations ● Accelerate KS binaries and multiples ● Reach limits of legacy code for re-writing? Data structure (currently moving data) Modularity (problems with stellar evolution/tidal fields) Hybrid Codes? (Meiron et al. 2014)
Meiron et al. 2014, ApJ
Summary Astrophysical High Precision N-Body – Star Clusters Ready for million particles, million core and Exascale, With GPU; Intel Phi still less performant Need more Dragon simulations to study physics of relaxation with different initial conditions Black Holes in Galactic Nuclei No stalling problem – robust result with rotation Enhanced tidal disruption rates due to: galaxy mergers / black hole kicks / rotation (Zhong et al. 2014, 2015, ApJ. Li et al. 2012 ApJ, 2015 subm. ApJ Khan et al. 2012 ApJ, Sobolenko et al. 2015 ApJ subm.) Further Astrophysical Science Drivers: Gravitational Waves Sky in Pulsar Timing Regime Effect of spinning black holes for: Tidal disruptions / SMBH mergers / GW signal
Recommend
More recommend
