With the  generous support of the Purple Mountain Astronomical Observatory, the  National Astronomical Observatories and the National Natural Science  Foundation, in a milestone development,  a team led by Professor Xiaowei  Liu from the Department of Astronomy and the Kavli Institute for  Astronomy and Astrophysics of Peking University, have recently completed  the data collection of a large CCD Photometric Survey of the Galactic  Anti-center, utilizing the1.04/1.20m Xuyi Schmidt Telescope. The survey  has been carried out in collaboration with Professor Haibin Zhao and  Jinsheng Yao of the Purple Mountain Astronomical Observatory which owns  and operates the Xuyi Near Earth Object Observatory.

The Xuyi  Schmidt Photometric Survey will provide positions and photometric data  and input catalog for the forthcoming Digital Sky Survey of the Galactic  Anti-center to be carried with the newly built national key  astronomical observing facility, the Guoshoujing Telescope, currently  under commissioning. Utilizing the 4,000 fiber afforded by the  Guoshoujing Telescope, the survey will eventually obtain intermediate  resolution optical spectra for a statistically complete sample of about  four million stars distributed in a contiguous sky area of over three  thousand square degrees in the direction of the Galactic anti-center.

The Xuyi  Schmidt photometric survey images, in three colors g-, r- and i-band  used by Sloan Digital Sky Survey, a sky area of over five thousand  square degrees centered on the Galactic anti-center, plus an extension  of over 300 square degrees to the area of the Andromeda Galaxy (M 31)  and the Triangulum Pinwheel Galaxy of the Local Group. Preliminary data  analyses show that the survey yields an astrometric accuracy of 0.1  seconds of arc and a photometric accuracy of 1 -  2 per cent, comparable  to the Sloan Digital Sky Survey. The survey reaches a limiting  magnitude of 20 and is expected to yield a catalog of over 100 million  Galactic stars.

Our own  Milky Way is an archetypical giant spiral galaxy or disk galaxy. The  disk, the defining component of the Milky Way, contains most of the  baryonic matter and essentially all the angular momentum of the galaxy.  Revealing the formation and evolution history of disk galaxies in the  bottom-up galaxy formation paradigm of the Lambda-CDM dominated  cosmological framework, i.e. how a disk galaxy like our own assembled  from pieces of pre-galactic substructures and acquired its  characteristic morphology, structure and chemical and kinematic  properties (the "grand design") is one of the most intriguing  astrophysical problems of the 21st century. The Xuyi Schmidt photometric  survey and the followup spectroscopic survey with the Guoshoujing  Telescope will provide a huge data set to tackle this forefront problem.  Its successful completion will signify the arrival of Chinese  astronomers at the central platform on the global stage and a  transitional shift in world's center of gravity in observational  astronomy.

DSS-GAC: A Digital Sky Survey of teh Galactic Anti-center: http://kiaa.pku.edu.cn/DSSGAC/news.html
Guoshoujing Telescope: http://www.lamost.org
Xuyi Near Earth Object Observatory: http://www.pmo.ac.cn/jgsz/gctz/xygcz/
Sloan Digital Sky Survey: http://www.sdss.org/

Figures:

The sky coverage of the Xuyi Schmidt  Photometric Survey (the central yellow dotted area) and the followup  Guoshoujing Telescope Spectroscopic Survey (yellow box at the center)

A g, r, i three band synthesized true color image obtained with the Xuyi Schmidt Telescope

The Xuyi Schmidt Telescope

The Guoshoujing Telescope