Galactic dynamics

What is dynamics?

Graviationall dynamical modelling uses kinematic data to infer the mass distribution in galaxies (including the Milky Way). The most important applicaiton is to figure out how dark matter is distributed in galaxies and how they are related to the stellar mass distribution. There are also curious scaling relations in galaxies, for example the masses of central supermassive black holes are tightly correlated with the velocity dispersions of galaxies. How do these correlations arise and what do they mean for galaxy formation are important issues that need to be understood, an area of research we are putting a lot of resources on.

My interests on Galactic dynamics

My main interests on galactic dynamics lie in two areas that are discussed below in turn. In short, we have been developing multiple techniques including the made-to-measure method , Jeans Anisotropic Method Jeans Anisotropic Multi-Gaussian Expansion method and the Schwarzschild method to perform dynamical modellings.

I. Dynamics of the Milky Way

The arrival of GAIA is going to revolutionise the study of the Milky Way. In the interim, we are using data from the LAMOST survey to infer the local dark matter distribution and velocity substructures. We are also trying to understand the parameters for the bar in the Milky Way.

II. Dynamics of nearby galaxies

With my students and postdocs, and as a consortium member of the SDSS-IV, we are studying the dynamics of nearby galaxies using the MaNGA survey which will eventually produce Integral Field Unit (IFU) data for 10,000 galaxies. We are currently studying the initial mass function of galaxies and also the chemo-dynamical correlation of galaxies.
MaNGA obtains spectra across the entire face of target galaxies using custom designed fiber bundles. The bottom right illustrates how the array of fibers spatially samples a particular galaxy. The top right compares spectra observed by two fibers at different locations in the galaxy, showing how the spectrum of the central regions differs dramatically from outer regions. Image Credit: Dana Berry / SkyWorks Digital Inc., David Law, and the SDSS collaboration. (taken from the SDSS-IV MaNGA web site)

Reviews on Galactic dynamics

This page is under construction. Last updated on Sept. 16, 2016