The GRACE Project Continuation 2010/2011

Astrophysical Computer Simulations using Programmable Hardware

(Application approved by Volkswagenstiftung Spring 2010)

• Objective 1: Develop a green, reconfigurable and hardware-accelerated cluster, and software tools that facilitate programming of such clusters for several applications in an international cooperation framework.
• Objective 2: Use the new cluster in production for key physical and astrophysical applications of the local teams: (i) Understand formation and co-evolution of massive black holes with the central region of galaxies including a detailed prediction of gravitational wave emission. (ii) Understand the complete life cycle of star clusters in the Milky Way, from their formation in the turbulent interstellar gas to their dispersal over secular timescales.

(i) ZITI Team together with application teams: Our primary goal in this project is to develop programming tools that enable astrophysicists to develop high performance code easily and efficiently for next generation heterogeneous energy efficient clusters, which will contain GPU, FPGA, or a combination of these with yet unknown new devices. This should be achieved through a unifying programming approach. It will be based on OpenCL, a parallel programming language specified end of 2008 by an international consortium. It should allow to program the cluster level, the many-core level, and the GPUs. (ii) Based on our current development for GPU programming using CUDA, we will extend OpenCL programming also to FPGA coprocessors. Our international cooperation partners ( CS Berkeley, USA and in Beijing, China will focus on the multi-core and GPU level. It is our goal to implement a consistent software environment of our systems, which allows mutual interoperable use for a larger number of applications, as compared to the case where each group would only care for a small number of applications in which they are interested.

Astrophysical Science Goals:

(i) ARI-ZAH Team: The first astrophysical goal is the study of formation, evolution and interactions of supermassive black holes (SMBH, masses of one million solar masses and more) in concert with their host galaxies. If galaxies merge in the course of their evolution, also their central SMBHs could merge. This is thought to be a source of gravitational wave emission as will be detected with the currently built gravitational wave detectors such as LISA or LIGO. There is observational evidence (existence of powerful jets in radio-loud active galactic nuclei (AGN), high accretion efficiency for radio-quiet quasars) that SMBHs have angular momenta close to the maximum values permitted by theory. Recent advances in numerical relativity and in approximate Post-Newtonian dynamics enable us for the first time to launch a detailed study of co-evolution of black holes and the stars in the center of their host galaxies including a detailed and relativistically correct angular momentum balance.

(ii) ITA-ZAH Team: (see also their project webpage ): The second astrophysical goal is to better understand formation and evolution of star clusters in our Galaxy. Stars and star clusters are the fundamental visible building blocks of spiral galaxies such as the Milky Way or neighboring Andromeda. Stars form in the interior of large clouds of hydrogen gas. Understanding the physical processes that regulate the conversion of gas into stars is central to much of modern astronomy and astrophysics. Stars have produced the bulk of all chemical elements heavier than H and He, and are responsible for almost all radiation at optical wavelengths. Stars thus are our primary source of astronomical information and, hence, are essential for our understanding of the universe and the physical processes that govern its evolution. Our goal is to study the formation of stars in the disk of Milky Way-type galaxies with exquisite detail and unprecedented predictive power.

Please send comments to: spurzem@bao.ac.cn .