I will briefly review recent development of observational cosmology, and
outline the importance of determining the mass of the Milky Way. Then I will
present the current status of the Milky Way mass measurement and discuss the
main uncertainties and shortcomings associated with previous methods. I will
then present our new method in order to overcome most of the drawbacks. The 6D
phase space distribution function of satellites is constructed from
cosmological simulations based on the similarity implied by the NFW profile.
Within the Bayesian statistical framework, we can not only infer the halo mass
efficiently, but also handle various observational effects including the
selection function, incomplete information (e.g., lack of proper motion), and
measurement errors in a rigorous and straightforward manner. Through mock
tests, we show that this method is accurate and unbiased, and superior to
methods solely based on Jeans theorem. We also demonstrate the satellite
galaxies are better tracers than stars in general. Applying our method to the
recent GAIA observations has yielded the most accurate determination of the
Milky Way mass. While the important application of our method is to measure
the Milky Way halo mass, it can be extended to any other galaxies or clusters
whose member satellites can be reliably identified.
Prof. Jing received his Ph.D. in Astrophysics from Int. Sch. Advanced Studies
(SISAA) of Italy in 1992. From 1993 to 2000, he worked in University of
Arizona, Max Planck Institute, Tokyo University as a research scholar in
Astrophysics. Prof. Jing joined the faculty of Shanghai Astronomical
Observatory in 1998, and the faculty of Shanghai Jiao Tong University in 2012.
He is the inaugural director of Center of Astronomy and Astrophysics in
Shanghai Jiao Tong University.