1. Introduction to the GRAPE

2. N-body : direct integration of the equations of motion Fokker-Planck : direct integration of the Fokker-Planck equation Monte-Carlo : particle-based method which uses Monte-Carlo to apply relaxation in the Fokker-Planck approximation Gas model : cluster modeled as conducting gas Hybrid methods : gas+MC, FP+N-body Numerical Methods for Dense Stellar Systems

3. The GRAPE project GOAL : Design and build specialized hardware for simulation of stellar systems. Rationale : You can do larger simulations (better resolution) for the same amount of money.

7. History of the GRAPE TABLE-1 Low-Precision machines Machine Year Peak speed GRAPE-1 1989 240 Mflop/s, GRAPE-3 1991 15 Gflop/s GRAPE-5 1998/9 ~ 1Tflop/s TABLE-2 High-Precision machines Machine Year Peak speed GRAPE-2 1990 40Mflop/s HARP-1 1993 180 Mflop/s GRAPE-4 1995 1 Tflop/s GRAPE-6 2002 64 Tflop/s

13. Sciences with the GRAPE Solar system / Planetary formation Star-forming region / Open clusters Globular clusters Galactic dynamics/ Galactic nuclei Galaxy formation Star formation Clusters of Galaxies / Cosmology (CDM halo)

14. More than just N-body SPH “GRAPE-SPH” - Nakasato & Nomoto, Matthias Steinmetz & Klaus Dolag, Volker Springe “Tree-GRAPE-SPH” MHD “Grape-MSPH” - Dolag et al. (1991, 2002) SPH simulations of magnetic fiels in galaxy clusters. K. Dolag. (A&A 348, 351, 1999) PM “Grape + PM” - Andreas Huss

16. Constructing a GRAPE Cluster 6,900,000 Yen for each GRAPE6-BLX64 board –Each BLX64 has 4 GRAPE chips –Total 132 Gflops 3,000,000 Won for each host PC –Two 2.0GHz dual-core Xeons, 1 GB memory 3,800,000 Won for one server PC –Two 2.0GHz dual-core Xeons, 1 GB memory

17. The Korean GRAPE Consortium 이형목 교수님 : 구매 진행 중 –2007 : 4 BLX64’s –2008 : 4 BLX64’s or DR ? SRC 멤버 : 3 월 구매 예정 –2007 : 4 BLX64’s –2008 : 4 BLX64’s or DR ? 공동연구 과제 신청 ? – 학진 기초과학 공동연구 : 1 억 / 년, 최대 3 년 (3 월 신청 ) – 과학재단 특정기초 :1 억 / 년, 최대 5 년 (5 월 신청 )

18. Proposed Research Topics Galactic Dynamics –Galactic warps : triaxial live halo –Galaxy interaction and evolution Galactic Center Hydrodynamics –200-pc molecular ring (the Central Molecular Zone) –5-pc molecular ring (the Circumnuclear Ring) Stellar Dynamics –Evolution of the globular cluster mass function –The Arches cluster Future Plans –Development of new codes (Monte Carlo simulations + GRAPE) –Planetary dynamics