Detecting the Stuff
Question: How do we know where gas is?
Question: What would be good and bad choices?
Interstellar Na absorbtion graphs
Growth curve and depletion factor graphs
Absorbtion by molecules
Absorbtion of UV photon
Energy levels and Molecular bands
H2 molecules
EUV and X-ray observations
Elliptical galaxy spectrum
X-rays in plasma
Question: Bremsstrahling emissivity
Optical emission lines
Radio-frequency observations
Rotational transitions of non-symmetric molecules
