The LEGUE disk targets for LAMOST's pilot survey

摘要

We describe the target selection algorithm for the low latitude disk por- tion of the LAMOST Pilot Survey, which aims to test systems in preparation for the LAMOST spectroscopic survey. We use the PPMXL astrometric catalog, which provides positions, proper motions, B/R/I magnitudes (mostly) from USNO-B and J/H/K s from the Two Micron All Sky Survey (2MASS) as well. We chose eight plates along the Galactic plane, in the region 0 < α < 67 and 42 < δ < 59 , which cover 22 known open clusters with a range of ages. Adjacent plates may have some small overlapping area. Each plate covers an area of 2.5 in radius, with its central star (for the Shack-Hartmann guider) brighter than 8 th magnitude. For each plate, we create an input catalog in the magnitude range 11.3 < I mag < 16.3 and B mag available from PPMXL. The stars are selected to satisfy the requirements of the fiber positioning system and have a uniform distribution in the I vs. B I color-magnitude diagram. Our final input catalog consists of 12 000 objects on each of eight plates that are observable during the winter observing season from the Xinglong Station of the National Astronomical Observatory of China.