An Inverse Problem Approach to Cluster Dynamics

Abstract

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.

arXiv comment30 pages, 12 figures, accepted for publication in the Astronomical Journal

References in corpus (7)

• High Proper Motion Stars in the Vicinity of Sgr A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy
• Star cluster ecology IVa: Dissection of an open star cluster---photometry
• The lives and deaths of star clusters near the Galactic center
• Structure and Mass of a Young Globular Cluster in NGC 6946
• The ionising cluster of 30 Doradus.IV. Stellar kinematics
• A Non-Parametric Estimate of the Mass of the Central Black Hole in the Galaxy
• The Dynamical Inverse Problem for Axisymmetric Stellar Systems

Cited by in corpus (6)

• Comparing X-ray and Dynamical Mass Profiles in the Early-Type Galaxy NGC 4636
• The Distribution of Dark Matter in the Halo of the early-type galaxy NGC 4636
• An Inverse Look at the Center of M15
• Plan beta: Core or Cusp?
• Mass Modelling with Minimum Kinematic Information
• Total mass distributions of Sersic galaxies from photometry $&$ cent\ ral velocity dispersion