6 February 2006

Supermassive Black Holes merge in Supercomputer GRACE

Astrophysicists of the Astronomisches Rechen-Institut (Zentrum für Astronomie) invite to the presentation of their new supercomputer and of first results on February 7, 2006, 3.00 p.m., seminar room, Mönchhofstr. 12-14, 69120 Heidelberg (with movie presentation)

New computer models of galaxies show a much faster merging of supermassive black holes in galaxies as previously thought. A combination of three favourable circumstances led to this result:

A more realistic initial model in the computer simulation, which takes into better account the rotation of galaxies. The scientific paper describing the results has been submitted at the beginning of this week to the renowned Astrophysical Journal Letters; a preprint is available online at http://arxiv.org/abs/astro-ph/0601698 .
A new kind of supercomputer GRACE, financed by the Volkswagenstiftung and the State of Baden-Württemberg (in cooperation with the universities of Mannheim and Munich), which achieves a speed of 3200 billion operations per second for the computer simulations. It provides a computing capacity locally which is only comparable with that of an entire supercomputing centre, which in addition has to share its compute power across many projects. Such computing power is a world record for such systems, combining normal PCs with special purpose hardware. The secret lies in special plugin cards, similar to graphics cards (picture) which are specialized for extremely fast computation of gravitational forces in astrophysical simulation software.
A graphical image processing software called SPIEGEL, developed by Hans-Peter Bischof of Rochester Institute of Technology (RIT) in New York State. Only with it the scientists could detect the critical hints in their simulation data. Heidelberg scientists have also cooperated in the assembly of a simular supercomputer there. http://www.cs.rit.edu/~grapecluster/



Upper left: 32 PCs constitute the compute cluster GRACE at the ARI. Upper right: every PC contains a GRAPE spezial compute board (identifiable for its large fan). GRAPE computers were developed by astronomers at the Univ. of Tokyo, Japan http://www.astrogrape.org Lower left: every PC gets an additional compute board, developed at the University of Mannheim (MPRACE) with a new kind of reconfigurable processor chip.

Schnappschüsse der neuen Simulationen mit dem GRACE-Rechner. Grüne Punkte: zentrale Schwarze Löcher; von links oben nach rechts unten zeitliche Entwicklung.

Figures from upper left to lower right: snapshots of the new simulations with the GRACE computer. Green dots: central black holes and their evolution in the galaxy; Clearly visible ist he formation of a barlike structure, as it is observed in many galaxies; in the last picture, after some 100 million years, the two black holes came close enough together, that they will undergo a fast merger under emission of gravity waves. Through these results new predictions for present and future space projects to measure gravity waves can be made; this would further solidify Einstein's theory of relativity.

This is a collaborative research with the departments of astrophysics (Prof. David Merritt) and computer science (Hans-Peter Bischof) at Rochester Institute of Technology (RIT), State of New York, USA.

Further Informations: http://www.volkswagenstiftung.de/presse-news/presse04/02072004.htm

Please address any inquiries to:
Questions to:
Prof. Dr. Rainer Spurzem
Astronomisches Rechen-Institut (ARI)
Zentrum für Astronomie Universität Heidelberg (ZAH)
Mönchhofstrasse 12-14, 69120 Heidelberg
Tel. 06221 541830, Fax 541888
spurzem@ari.uni-heidelberg.de

Dr. Michael Schwarz
Press Officer of the University of Heidelberg
phone: 06221/542310, fax: 54317
michael.schwarz@rektorat.uni-heidelberg.de
http://www.uni-heidelberg.de/presse/index.html