China, Japan build "sharp eyes" for further space observations

by Chinese media writer Wang Aihua

BEIJING, Feb. 10 (Chinese media) -- China and Japan are

making prominent contributions to a cutting-edge East Asian radio telescope

network by respectively building the world's top-level radio telescope apparatus

to be dedicated to further observations into the galaxy and black holes.

FAST, short for the Five-hundred-meter Aperture

Spherical Radio Telescope, is the world's largest-aperture radio telescope

announced so far and is under construction in a karst-landform village of

southwestern China's Guizhou Province.

Japanese astronomers, meanwhile, are planning to

launch the second generation of its world leading space radio telescope program

called VSOP-2 which allows satellites to carry antennae into the space and

therefore, expands the telescope network to beyond the earth's surface.

Mark J. Reid, astronomer at the Harvard-Smithsonian

Center for Astrophysics in the United States, told Chinese media in an email Tuesday,

the two apparatus would help East Asian astronomers play a large role in the

venture of space exploration.

"The huge FAST telescope will ultimately allow

detection of fainter sources of celestial bodies," Reid wrote, "and the Japanese

space antennae will yield the highest angular resolution possible."

Due to be completed in 2013, FAST could be used to

study physical laws of objects under extreme conditions and help search for

extraterrestrial civilizations by identifying possible interplanetary

communication signals, official website of the project said.

Japan's VSOP-2, second generation of the VLBI (Very

Long Baseline Interferometry) Space Observatory Program scheduled to launch in

2012, would further expand the baselines between the telescopes. Armed with

other advantages over the first generation such as higher observing frequencies

and increased bandwidths, the VSOP-2 would gain higher resolution and

sensitivity.

Radio telescopes differ from optical ones in that

they use radio antennae to track and collect data from satellites and space

probes. The VLBI technology used in radio telescopes combines the observations

simultaneously made by several telescopes to expand the diameter and increase

magnification.

The two apparatus, to be included in a large radio

telescope network called the East Asia VLBI consortium, could each cooperate

with the radio telescopes stationed on earth.

The consortium, whose full-scale observations are

expected to start in 2010, consists of 19 radio telescopes from China, Japan and

the Republic of Korea (ROK) that cover an area with a diameter of 6,000

kilometers from northern Japan's Hokkaido to western China's Kunming and Urumqi.

China's four telescopes participating in the

consortium are still focusing on tracking Chang'e-1, China's first lunar probe,

said Shen Zhiqiang, a VLBI researcher at the Shanghai Astronomical Observatory.

"But we are carrying out experimental observation

tests as much as possible to prepare for the cooperation with Japan and ROK,"

Shen said.

The Korean side, with three telescopes to join the

network, is working with the Japanese on building a correlator to be put in use

by end of next year in Seoul.

Se-Hyung Cho, initiator of the Korean VLBI Network

(KVN), told Chinese media in an email, the correlator combines the observed data from

each station of the East Asia VLBI consortium for synthesized high-resolution

images.

Korean astronomers will design their observational

study based on available "spatial resolutions and sensitivities" - ability to

obtain clear images of the observed object, of the East Asia VLBI network, Cho

wrote.

The first radio antenna used to identify astronomical

radio sources was built by Karl Guthe Jansky, an engineer with Bell Telephone

Laboratories, in the early 1930s.