21-element infrared adaptive optics system at 2.16-m telescope

摘要

Abstract: A 21-element adaptive optics system installed at the2.16m telescope of Beijing Astronomical Observatory hasbeen in operation. It is made up of a pair of shearinginterferometer (SI), a 21-element deformable mirror, afast steering mirror, a digital wavefront processor, aprecise tracking subsystem and a PtSi IR CCD camera. Inthis paper the performance of the system will bebriefly introduced. Its observation results in IR Kband and in visible band are reported. For the system,0.25 arcsec resolution has been achieved in IR K band,which approaches the diffraction limit of the 2.16maperture. In visible band, 0.13arcsec resolution hasbeen also achieved. For the star of magnitude 9.$+m$/2,the compensation of the system is still effective. Theerror rejection bandwidth of the system can be adjustedin the range from 5Hz to 40Hz according to the beaconmagnitude and the strength of the atmosphericturbulence. !6