Scientists from around the world are engaged in building a new generation of observatories, with larger effective areas and higher resolutions, to probe the very early universe.
"To reach the sensitivity required to image these first discrete objects in the universe needs a major advance in X-ray optics," said Prof. Martin Elvis, of the Harvard-Smithsonian Center for Astrophysics (SAO), at a scientific session of the ongoing 36th Committee on Space Research (COSPAR) Scientific Assembly in Beijing.
Generation-X, the next high resolution X-ray observatory, a mission led by the SAO aims to improve substantially on the angular resolution with larger effective area, which will have 1,000 times greater sensitivity than current X-ray telescopes, according to Prof. Elvis.
The objectives of the mission include observation of the birth of the first generation of black holes, stars and galaxies, tracing the temporal evolution of black holes and galaxies and probing the behavior of matter in extreme environments.
To achieve these goals, the study team has adopted an approach based on active X-ray optics that will have active on-orbit figure control.
"A lab version of these optics has been developed and is successfully operating at synchrotron light sources," said Prof. Elvis.
Since the Earth's atmosphere absorbs the vast majority of X-rays, they are not detectable from Earth-based telescopes, requiring a space-based telescope to make these observations.
Launched in July 1999, the Chandra telescope contains four sets of nested mirrors and is the premier X-ray observatory to date.
However, the low effective area/unit mass of the Chandra optics precludes simply scaling the Chandra design to much larger areas.
The Generation-X, with 100 square meters of effective area and 0.1 arcsecond angular resolution, will be able to look deeper into the past.
The main challenge for Generation-X was the mirror technology, which needed a hundredth of the Chandra mass/area unit, but ten times better angular resolution.
The Generation-X mission had been included in the US National Aeronautics and Space Administration (NASA) plan, he said.
Meanwhile, scientists in other countries are also working on observatories to detect ultraviolet, infrared, X-ray and gamma radiation.
The X-ray Evolving Universe Spectroscopy (XEUS) space observatory is being developed by the European Space Agency as a successor to the XMM-Newton X-ray satellite telescope. It will be able to measure the X-ray spectrum and thereby the composition, temperature and velocities of hot matter in the early universe.
The Japan Aerospace Exploration Agency (JAXA) launched an X-ray astronomy satellite with telescope Suzaku in 2005 to perform broadband observations and high resolution spectroscopy. A new project with fine spectrometers called NeXT will be launched in 2012.
(Xinhua News Agency July 21, 2006)
