The SAO Terahertz Toolbox includes a database of spectroscopic
parameters for use in THz astronomical measurements and analyses (the
SAO THz database), as well as web-based programs for utilizing the
database in analysis of astronomical measurements. The toolbox
includes the capability to calculate spectra, including atmospheric
transmission and sky brightness as well as astronomical sources, for
mission planning, and data fitting and analysis capability. Spectra
can be calculated for high-altitude terrestrial sites, aircraft and
balloon platforms, and space-based measurements.
The THz region is gaining increased relevance for astronomy, in galactic source studies, details of astrochemistry, and cosmological and extragalactic studies. Measurements are becoming more technically feasible and suitable observing sites are being developed (e.g. in Chajnantor and Sairecabur, Chile and in Antarctica). Important new space- and aircraft-based missions are coming online: The Space InfraRed Telescope Facility (SIRTF, 2003), the Stratospheric Observatory For Infrared Astronomy (SOFIA, 2004) and the Herschel Mission (2007).
This current, preliminary, version of the SAO THz database covers the 1-1.6 THz region; it will be extended to at least 0.5-3 THz as astronomical needs require. It includes atmospheric molecules, with extension to higher excitation energies (H2O and minor H2O isotopomers, and hot CO), small non-atmospheric species and atomic and molecular ions. It is closely coordinated with the HITRAN database, which also is maintained at the SAO. Fitting and analysis programs are not yet installed on this website, although they exist off line. Data sources include up-to-date laboratory measurements and previously cataloged parameters.
The initial database includes: H2O, H217O, H218O, HDO, O3, 16O16O18O, 16O18O16O, CO, 13CO, C18O, H35Cl, H37Cl, HCN, HNC, NH, SO, CS, C34S, CN, CCH, KH, MgH, SiH, SiO, FeH, N+, NH+, OH+, CO+, HCO+, HCS+, and H3O+.