Estimation of the distribution function f and potential O of hot stellar systems from kinematical data is discussed. When the functional forms of f and O are not specified a priori, accurate estimation of either function requires very high quality data : either accurate "line profiles" at radii extending well beyond an effective radius, or large samples (N > 10^3) of discrete radial velocities. Estimates of O(r) based on much smaller data sets can be very strongly inuenced by assumptions, explicit or implicit, about the form of f. The importance of casting the estimation problem into a mathematically determined form is stressed. Some techniques for nonparametric estimation are presented, with some preliminary results of their application to real stellar systems (Refer to PDF file for exact formulas).
Date of creation, presentation, or exhibit
Department, Program, or Center
School of Physics and Astronomy (COS)
Merritt, David, "Dynamical modelling of hot stellar systems" (1993). Accessed from
RIT – Main Campus