Current proposed TMT observatory contains 8 instruments, with 3 instruments available at first light, and five available in the first decade (see Table 1). At first light, TMT will employ a laser guide star supported, multi-conjugate adaptive optics system called NFIRAOS (Narrow Field Infrared Adpative Optics System), which will provide diffraction-limited resolution and high Strehl ratios over a 30 arcsec field-of-view. The resolution at 1 micron is about 7 milli-arsecond, roughly a factor of ten higher than that of HST.
The three early light instruments are
WFOS: a wide-field, multi-object spectrograph working at optical wavelengths (0.31 to 1.1 microns). It has impressive multiplex capabilities. Using separate masks, it is possible to observe up to 1500 objects over a 40.5 square arc-minutes with spectral resolution from 300-7500.
IRIS: an integral-field unit (IFU) spectrometer with imaging capability working at near-infrared wavelengths (0.8-2.5 microns). The imaging mode will provide a 10x10 arcsec field of view with 0.004 arcsec/pixel sampling. The IFU will provide spectral resolving power of 4000 over the J, H and K bands. This instrument will be ideal to study the kinematics of galaxies in great detail.
IRMS: a multi-slit, near-infrared (0.8-2.5 microns) spectrometer with imaging capability. It will provide 46 movable, continuously variable width cryogenic slits. The two-pixel resolving power is 4660 covering Y, J, H and K bands. In the imaging mode, IRMS covers the entire NFIRAOS field of view with 0.06 arcsec sampling.
The latter two instruments will be fed by NFIRAOS to achieve full diffraction-limited sensitivities and spatial resolutions in the near-infrared. These three instruments will be capable of exploring a wide astronomical terrain: from the first stars in the Universe to the planets orbiting nearby stars.
The proposed five first-decade instruments will be developed and deployed on a schedule depending on a combination of technological readiness and available financial resources. The basic technical information about the three early light instruments and five first decade instruments are listed in Table 1. Notice that the TMT has a total field of view of 20, with 15 un-vignetted. The instruments in Table 1 use only part of this FOV.
Table 1: instruments and sciences of TMT. The top three instruments (light shaded) are the early light instruments, while the five first-decade instruments are shown below. The acronyms are listed in Appendix A. For diffraction-limited observations, the resolution is ≈7mas (/m). Taken from the TMT documents. 6>