Difference between revisions of "Research Interests"

Revision as of 09:24, 9 September 2014

Our research aims are to study the formation, evolution, and structure of galaxies. A central theme of the group’s research for many years has been stellar clusters and the structure of the Milky Way.

Stars and the Galactic structure

Characterising and classifying the stars around us is crucial if we are to use them to study the structure of our galaxy. Spectroscopic surveys such as LAMOST are providing spectra for millions of stars, but only by determining properties such as stellar types (and hence distances) and ages will we be fully able to exploit these datasets. Meanwhile, we are able to discover a large sample of Hyper-velocity stars, which will provide unique constraints on the shape of the potential of the Galaxy’s dark matter halo.

Open clusters (OCs)

OCs have long been used to trace the structure and evolution of the Galactic disk. Open clusters have relatively large age & distance spans and can be relatively accurately dated; the spatial distribution, kinematical properties and metalicities of OCs provide critical constraints on the overall structure and chemical and dynamical evolution of the galactic disk;

LAMOST and Galactic Substructures

The present state of our galaxy can tell us a lot about how it has formed and evolved. In particular the stellar halo contains satellite galaxies and relics of accretion events, resulting in many substructures and streams. By discovering and analysing these substructures we can probe the details of hierarchical assembly and confront predictions from cosmological simulations.

Galactic Chemical Evolution (GCE) model

GCE is the study of the evolution in time and space of the abundances of the chemical elements in the interstellar medium (ISM) in galaxies. As the template of disk galaxies, the Milky Way galaxy is the best sample in testing the usefulness and importance of the GCE theory. By comparing the GCE results with the observations, we are able to understand how our Galaxy was assembled, what is the history of star formation and gas accretion during the evolution of the Galaxy.

international collaborations

In addition to above research topics, we also have fruitful international co-operations with Germany (MPA), Canada (DAO), France (IAP), and the USA (UMASS) through visiting scholars, student exchanges, and joint observation programs.

One can learn more about our research from our publications.

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 The present state of our galaxy can tell us a lot about how it has formed and evolved. In particular the stellar halo contains satellite galaxies and relics of accretion events, resulting in many substructures and streams. By discovering and analysing these substructures we can probe the details of hierarchical assembly and confront predictions from cosmological simulations.
-A spectroscopic survey of stars by LAMOST would be able to acquire more than 5 million stellar spectra, with a radial velocity accuracy at the level of 5-15 km/s. Identifying hypervelocity stars from the LAMOST survey is essentially straightforward once the spectra are acquired, and covers a wide range of spectral type. Compared with the present HVSs sample, the LAMOST survey will likely increase the HVSs sample by about one order of magnitude or more. The large statistical sample of HVSs of different types discovered by LAMOST will be a powerful tool to deepen our understanding of the properties of the Galaxy.
 ==Galactic Chemical Evolution (GCE) model==