ﻻ يوجد ملخص باللغة العربية
We present a new framework for estimating a galaxys gravitational potential, Phi(x), from its stellar kinematics by adopting a fully non-parametric model for the galaxys unknown action-space distribution function, f(J). Having an expression for the joint likelihood of Phi and f, the likelihood of Phi is calculated by using a Dirichlet process mixture to represent the prior on f and marginalising. We demonstrate that modelling machinery constructed using this framework is successful at recovering the potentials of some simple systems from perfect discrete kinematical data, a situation handled effortlessly by traditional moment-based methods, such as the virial theorem, but in which other, more modern, methods are less than satisfactory. We show how to generalise the machinery to account for realistic observational errors and selection functions. A practical implementation is likely to raise some interesting algorithmic and computational challenges.
One of the major goals of the field of Milky Way dynamics is to recover the gravitational potential field. Mapping the potential would allow us to determine the spatial distribution of matter - both baryonic and dark - throughout the Galaxy. We prese
WLM is a dwarf irregular that is seen almost edge-on that has prompted a number of kinematical studies investigating its rotation curve and its dark matter content. In this paper, we investigate the origin of the strong asymmetry of the rotation curv
We revisit the two-component virial theorem (2VT) in the light of recent theoretical and observational results related to the dark matter(DM) problem. This modification of the virial theorem offers a physically meaningful framework to investigate pos
When dark matter structures form and equilibrate they have to release a significant amount of energy in order to obey the virial theorem. Since dark matter is believed to be unable to radiate, this implies that some of the accreted dark matter partic
We explore the distribution of RMS=SFR/SFR_MS (where SFR_MS is the star formation rate of Main Sequence star-forming galaxies) for AGN hosts at z=1. We split our sample into two bins of X-ray luminosity divided at Lx=2x10^43erg s-1 to investigate whe