Herschel Space Observatory - Theoretical Research Proposal #1018

THz Time Domain Spectroscopy of Astrophysical Dust Analogs, Ices, and Complex Organics

Principal Investigator: Geoffrey Blake 
           Institution: Caltech 

Dollars Approved: 175000

Abstract:
Photons at far-infrared (far-IR)/TeraHertz (THz) frequencies hold the keys to many
of the outstanding issues in astrophysics. To fully realize the promise of Herschel,
however, it is essential that we achieve a quantitative experimental understanding
of the far-IR properties of the dust, ice, and gas which make up the ISM; yet THz
laboratory studies largely lag behind the astronomical capabilities that Herschel
will deploy, thanks primarily to technological limitations. Here we propose to use
femtosecond THz Time Domain Spectroscopy (THz TDS) to acquire high dynamic range
optical constants of the major components that comprise astrophysical dust and ice
across the full wavelength region accessible to Herschel and over temperatures from
7-300 K. We also propose to study the lowest frequency skeletal vibrations of PAHs
and the torsions of complex organics such as glycine in both the solid state and gas
phase in order to permit Herschel studies of prebiotic chemical evolution.