Submillimeter astronomy and developments in China

Millimeter to submillimeter radio astronomy is one of the frontier areas in Chinese astronomy. The major research activities include molecular clouds, star formation, formation and evolutions of galaxies. Purple Mountain Observatory (PMO) is the major institute in China responsible for mm/submm astronomy and developments. PMO is operating the 14m mm-wave radio telescope at Delingha, west China. Recently, a 3×3 sideband separation SIS array receiver was developed. This receiver was installed onto the telescope and has been used for a large-scale survey of the northern Galactic Plane since 2011, typically under the ¹²CO/¹³CO/C¹⁸O multi-line mode in the 3mm waveband. This instrument makes the telescope very efficient in line survey. Chinese institutes have been involved in a number of international collaboration in submm/THz developments. PMO involved at SMA (through ASIAA) and ALMA (Band 8 & Band 10 R&D through NAOJ). Recently, China also worked with the Herschel/SPIRE and KOSMA by teams from NAOC, and on a space VLBI project by teams from SHAO. Joint international effort has been made for THz site evaluation at Dome A, Antarctica, which is suggested as the best ground-based THz site. On the basis of the site conditions, China started to work on conceptual studies for the 5m THz telescope proposed for Dome A (5m Dome A THz Explorer, DATE5), which is one of the two major telescopes proposed for Dome A observatory.