Search arXivSearch

arXiv · 0711.4655

GRAvitational COSmology (GRACOS) code release announcement, for version 1.0.1a9

Abstract

This is to announce a recent release of version 1.0.1a9 of parallel load balanced adaptive P3M cosmological N-body code named GRACOS. The code has been under development over years and is available for the download at http://www.gracos.org. GRACOS features: embedded script environment, cosmological initial conditions generator including non-gaussian initial conditions, particle data imager, mass density power spectrum estimator, particle position and velocity integrator with a choice between KDK and DKD integration schemes with Plummer force softening, file input and output with four supported serial and one dynamic distributed data format, standard installation procedure, and version specific documentation. GRACOS is released under the GNU General Public License (GPL). High efficiency is achieved with a number of implemented techniques such as timer-based load balancing using Hilbert space filling curve, adaptive P3M method for short range force computation, run-level compression in interprocessor communication, dynamic allocation for irregular domains and various sorting algorithms.

Explore related subjects

Keep this discovery

BibTeXRIS

Alexander Shirokov. 2007-11-29. GRAvitational COSmology (GRACOS) code release announcement, for version 1.0.1a9. https://arxiv.org/abs/0711.4655

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Black Stars and Gamma Ray Bursts

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed "black stars". Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

astro-ph

Kinematic Control of the Inertiality of ICRS Catalogs

We perform a kinematic analysis of the Hipparcos and TRC proper motions of stars by using a linear Ogorodnikov-Milne model. All of the distant (r more than 0.2 kpc) stars of the Hipparcos catalog have been found to rotate around the Galactic y axis with an angular velocity of -0.36 +/- 0.09 mas/year. One of the causes of this rotation may be an uncertainty in the lunisolar precession constant adopted when constructing the ICRS. In this case? the correction to the IAU (1976) lunisolar precession constant in longitude is shown to be -3.26 +/- 0.10 mas/yr. Based on the TRC catalog, we have determined the main Oort constants: A = 14.9 +/- 1.0 and B = -10.8 +/- 0.3 km/s/kpc. The component of the model that describes the rotation of all TRC stars around the Galactic y axis is nonzero for all magnitudes, My= -0.86 +/- 0.11 mas/yr.

astro-ph

Astrometric Control of the Inertiality of the Hipparcos Catalog

Based on the most complete list of the results of an individual comparison of the proper motions for stars of various programs common to the Hipparcos catalog, each of which is an independent realization of the inertial reference frame with regard to stellar proper motions, we redetermined the vector $ω$ of residual rotation of the ICRS system relative to the extragalactic reference frame. The equatorial components of this vector were found to be the following: $ω_x = +0.04\pm 0.15$ mas yr$^{-1}$, $ω_y = +0.18\pm 0.12$ mas yr$^{-1}$, and $ω_z = -0.35\pm 0.09$ mas yr$^{-1}$.

astro-ph