Redshifted UV Astronomy with the next generation space telescope Available to Purchase

The Next Generation Space Telescope, as currently conceived, will have an aperture $>4 m$ and will be optimized for observations in the near infrared, 1–5 μm for studies of the origins of stars and galaxies at high redshift $z.$ Its scientific charter comes from the HST and Beyond report (1996). Initial study results by three engineering teams show that a telescope of aperture up to 8 m could be launched by 2007 with a construction phase budget of $500 M, providing that adequate technology development is done prior to the start around 2003. The telescope would be placed far from Earth, at the Lagrange point L2 or beyond, allowing radiative cooling of the telescope to 30–80 K. It would use hundreds to thousands of optical adjustments to achieve the required figure accuracy. The instrument package would include wide field cameras and multi-object spectrometers for the core scientific program. Extension of the wavelength range to cover at least 0.5 to 20 μm is highly desirable. Detectors for 0.5 to 5 μm could be InSb, while the 5–10 μm range can be covered by HgCdTe and the 5–25 μm range can be covered with the Si:As. With these concepts, the sensitivity achieved would be in the nanojansky range; $1 nJy=31.4$ magnitudes on the $ABν$ scale. Supernovae and star forming regions of early globular clusters and galactic centers could be seen to redshifts of 10 or more. Such a telescope would also be a powerful tool in the study of planet and star formation, circumstellar disks, and the planets, satellites, asteroids, comets, and Kuiper belt objects in our own Solar system.