ar X iv : a st ro - p h / 04 06 12 8 v 1 4 J un 2 00 4
نویسنده
چکیده
We propose a new non-parametric algorithm that can be implemented to study and characterize stellar clusters. The scheme attempts to simultaneously recover the stellar distribution function and the cluster potential by using projected radii and velocity information about the cluster members. The pair of these functions that is most consistent with the input data is detected by the Metropolis algorithm. In this work, the cluster characteristics recovered by CHASSIS are calibrated against the N-body realizations of two clusters, namely Hyades and Arches. The cluster mass and line-of-sight projected velocity dispersion profiles are correctly reproduced by the algorithm when the cluster obeys the assumption used in the code, namely isotropy in phase space. The results recovered by the code are shown to be insensitive to the choice of the initial parameters. The results are also not influenced by increasing the number of input data points as long as this number exceeds a minimum value which is moderately low for an input data set that obeys the assumptions of isotropy and sphericity. Subject headings: Galaxy: center; Galaxy: kinematics and dynamics
منابع مشابه
ar X iv : a st ro - p h / 06 06 12 4 v 1 6 J un 2 00 6 Inhomogeneous Cosmology , Inflation and Late - Time Accelerating Universe
An inhomogeneous cosmology describing a spacetime without symmetry is shown to be able to inflate the early universe and explain the late-time acceleration of the universe without a cosmological constant and negative pressure dark energy and avoid the coincidence problem. e-mail: [email protected]
متن کاملar X iv : a st ro - p h / 06 12 37 8 v 1 1 4 D ec 2 00 6 Magnetic fields , strings and cosmology
متن کامل
ar X iv : a st ro - p h / 04 01 12 2 v 1 8 J an 2 00 4 High Energy Gamma - Ray
The physics results of high energy γ-ray astronomy are reported, emphasizing recent achievements with ground-based detectors. This includes some of the instrumental developments and latest projects. The fundamental contribution of the field to the question of Cosmic Ray origin is highlighted.
متن کاملar X iv : a st ro - p h / 00 06 14 2 v 1 9 J un 2 00 0 1 Simulation of Water Cerenkov Detectors Using geant 4
We present a detailed simulation of the performance of water Cerenkov detectors suitable for use in the Pierre Auger Observatory. Using geant4, a flexible object-oriented simulation program, including all known physics processes, has been developed. The program also allows interactive visualization, and can easily be modified for any experimental setup.
متن کاملar X iv : a st ro - p h / 06 04 29 8 v 2 1 4 A pr 2 00 6 the Non - Gaussianity of Racetrack Inflation Models
In this paper, we use the result in [7] to calculate the non-Gaussianity of the racetrack models in [3, 5]. Our results show that the nonGaussianity in [3] is reasonable, while the non-Gaussianity in [5] is beyond the observational limits. PACS: 98.80.Cq, 98.80.Jk, 04.20.Gz
متن کامل