NGST: Seeing the First Stars and Galaxies Form

Abstract

The Next Generation Space Telescope (NGST) is a key element in NASA’s Origins program. The primary goals for the NGST are observing the origins of stars, galaxies, and the elements that are necessary for life. To reach those goals, the telescope must work in the near and mid-infrared — at wavelengths where the Earth’s atmosphere outshines the distant galaxies by up to 8 orders of magnitude. NASA, industry, US astronomers and international collaborators have completed the initial feasibility study and have begun the development of the technologies required to make the mission affordable and ready to launch by 2007.

We describe the three missions developed in the feasibility studies: a 6 m monolithic telescope in a 1 × 3 AU elliptical orbit, and two 8 m deployable telescopes put into L2 halo orbits. All three telescopes are radiation cooled to temperatures of 30–60 K. All three achieve point-source imaging sensitivities of 1 nanoJansky in a 3 hr exposure. Such sensitivity and diffraction-limited imaging can see the birth of stellar clusters at redshifts of z = 10 – 20 - even before the universe was reionized. We also illustrate NGST’s potential for studying the detailed interactions and mergers of galaxies during the peak of metal production at redshifts of z = 1 – 2, an epoch when dust may mask much of the galactic light and the regions of ongoing star formation.