ar X iv : a st ro - p h / 98 11 41 8 v 1 2 6 N ov 1 99 8 Astrophysics on the GRAPE Family of Special Purpose Computers Piet Hut Institute for Advanced Study

ar X iv : a st ro - p h / 97 04 27 7 v 1 2 8 A pr 1 99 7 The GRAPE - 4 , a Teraflops Stellar Dynamics Computer

Recently, special-purpose computers have surpassed general-purpose computers in the speed with which large-scale stellar dynamics simulations can be performed. Speeds up to a Teraflops are now available , for simulations in a variety of fields, such as planetary formation, star cluster dynamics, galactic nuclei, galaxy interactions, galaxy formation , large scale structure, and gravitational le...

ar X iv : a st ro - p h / 98 11 24 4 v 1 1 6 N ov 1 99 8 Fast X - ray Variability of PKS 2155 – 304 : A Cross

ar X iv : a st ro - p h / 98 04 08 9 v 1 8 A pr 1 99 8 STELLAR DYNAMICS OF DENSE STELLAR SYSTEMS

Stellar dynamics is almost unreasonably well suited for an implementation in terms of special-purpose hardware. Unlike the case of molecular dynamics, stellar dynamics deals exclusively with a long-range force, gravity, which leads to a computational cost scaling as the square of the number of stars involved. While special tricks can lead to a reduction of this cost from ∼ N 2 to ∼ N log N in t...

ar X iv : a st ro - p h / 98 11 19 7 v 1 1 2 N ov 1 99 8 The ‘ bare ’ strange stars might not be bare

ar X iv : a st ro - p h / 98 11 07 8 v 2 6 N ov 1 99 8 Selection Effects at 21 cm

Surveys in the 21cm line of neutral hydrogen are testing the completeness of the catalogs of nearby galaxies. The remarkable observational fact is that the potential wells that confine gas to sufficient density that it can remain neutral in the face of ionizing radiation also provide sites for star formation, so that there are no known cases of neutral intergalactic clouds without associated st...