The CCOSMA (China-Cologne Observatory for Sub-millimeter Astronomy) was a sub-millimeter telescope located on YangBaJing Observatory of NAOC (National Astronomical Observatories, Chinese Academy of Sciences) in Tibet. We got the first light on October 31th successfully with the joint efforts of Sino German Scientific and technical staff. ?The first light is the transition lines of CO (3-2), CO (2-1) at 345GHz and 230GHz from DR21 star forming region (As shown in the figure).

Since 2009, NAOC combined with other domestic university and institute worked together with university of Cologne to move KOSMA (Now this 3-m sub-millimeter telescope is renamed CCOSMA) from Gornergrat?near?Zermatt?(Switzerland) to YangBaJing?in?Tibet?(China) at an altitude of 4300m. The staffs of this team overcame lots of difficulties in poor conditions and bad environments to build the YangBaJing Observatory in Tibet. From 2010 to 2011, we disassembled the telescope in Switzerlandthen. After transit, it was reinstalled on the new site. The YangBaJing Observatory was established in the same year. In 2012, the receiver was cooled down to 4.5K. The receiver and AOS worked well. The upgrade of electric control and drive system was done in 2013. In 2014, we debugged and modified the software and hardware for the first light, after that we got the first light.

We can use this telescope to detect the emission line of Interstellar molecules of the embedded protostar in Interstellar gas and dust for star formation study. Also it could play important role in Galactic plane survey of?the?northern?sky. It had been the first sub-millimeter telescope for routine science observation in China, and the sub-millimeter telescope with highest site in northern hemisphere so far.

The exterior view of the station