SWS Central Program--- ISM (130 hr; 30%)

• Dense, warm molecular gas in a variety of conditions (Drapatz et al.).
  • Photon-dominated (reflection nebulae).
  • Shocked molecular gas.
  • Environments of embedded sources.
  • X-ray excited gas.
• Diagnostic molecular emission & absorption lines (van Dishoeck et al.).
  • Sample wide range of gaseous and solid state molecular species.
  • SWS grating resolution well matched for fine structures in solid features.
  • Study abundance and excitation: H_2, HD, H_2_O, OH, CO_2, etc.
  • FP resolution critical here.
  • Vibration-rotation absorption lines of ISM molecules.
  • Circumstellar molecules.
  • Emission lines of H_2, HD, OH and H_2_O.
• Composition, structure and evolution of dust grains (Whittet et al.).
  • Determine abundances of organic molecules (CO_2, CH_4, etc.) in grain mantles.
  • 12C/13C ratio measuded using 4.3 um CO_2 resonances.
  • Hydration studies in 2.6 -- 2.9 um band.

• SWS Scientific Capabilities (Back)