Dr. Riccardo Giacconi, University Professor of Johns Hopkins University and the Nobel Prize winner for physics in 2002, visited Purple Mountain Observatory on October 22 – 23, 2008. He gave a one-hour talk on “The Impact of Modern Telescope Development on Astronomy”. After the talk, Dr. Giacconi had an informal discussion with several research professors and scientists, and gave advisory opinions on future space astronomy and THz research of Purple Mountain Observatory. He visited the millimeter and sub-millimeter wave laboratory, the space astronomy laboratory, and the ancient Chinese astronomical instruments on top of the Purple Mountain with great interest. Directors of the observatory, Drs. Chunlin Lu, Weiqun Gan and Ji Yang, briefly introduced the current state of development of Purple Mountain Observation to Dr. Giacconi during his visit.

　A brief introduction of Dr. Riccardo Giacconi: Dr. Giacconi was born in Genoa, Italy, on October 6, 1931. He spent brief postdoctoral periods at Indiana and Princeton Universities in USA after he earned his PhD at University of Milan. In 1959 he joined American Science and Engineering, a Massachusetts research firm, where he began work on X-ray astronomy. His team developed grazing incidence X-ray telescopes and launched them on rockets. In 1962 they discovered Scorpius X-1, the first known X-ray source outside the solar system. They then built the UHURU orbiting X-ray observatory and made the first surveys of the X-ray sky. They discovered 339 X-ray “stars”, most of which turned out to be due to matter falling into black holes and neutron stars. Among these was Cygnus X-1, the first object to be widely accepted as a black hole. They also discovered the X-ray emission by hot gas in clusters of galaxies. Giacconi has continued to work on the X-ray background radiation for many years using a number of satellite observatories. Joining the Harvard-Smithsonian Center for Astrophysics in 1973, Giacconi led the construction and successful operation of the powerful X-ray observatory, HEAO-2, also known as Einstein, which made detailed images of X-ray sources. Giacconi was the first director of the Space Telescope Science Institute from 1981 to 1993, and he directed the European Southern Observatory for the next six years. At ESO he oversaw the development and construction of the Very Large Telescope. From 1999 to 2004 he served as president of Associated Universities, Inc., the operator of the National Radio Astronomy Observatory. In this position he was involved in the development of the Atacama Large Millimeter Array (ALMA), a huge millimeter and sub-millimeter wavelength array being built at high altitude in Chile by a team of European, American, and Japanese institutions. Giacconi has simultaneously held positions as professor of physics and astronomy (1982-97) and research professor (since 1998) at Johns Hopkins University.