Science with the James Webb Space Telescope
Jonathan P. Gardner
The deepest optical to infrared observations of the universe include
the Hubble Deep Fields, the Great Observatories Origins Deep Survey
and the recent Hubble Ultra-Deep Field. Galaxies are seen in these
surveys at redshifts z>6, less than 1 Gyr after the Big Bang, at the
end of a period when light from the galaxies has reionized Hydrogen
in the inter-galactic medium. These observations, combined with
theoretical understanding, indicate that the first stars and galaxies
formed at z>10, beyond the reach of the Hubble Space Telescope. To
observe the first galaxies, NASA is planning the James Webb Space
Telescope (JWST), a large (6.5m), cold (50K), infrared-optimized
observatory to be launched early in the next decade into orbit around
the second Earth-Sun Lagrange point. JWST will have four instruments:
The Near-Infrared Camera, the Near-Infrared multi-object
Spectrograph, and the Tunable Filter Imager will cover the wavelength
range 0.6 to 5 microns, while the Mid-Infrared Instrument will do
both imaging and spectroscopy from 5 to 27 microns. In addition to
JWST~Rs ability to study the formation and evolution of galaxies, I
will also briefly review its expected contributions to studies of the
formation of stars and planetary systems.