Syllabus+(Spring),+Interstellar+Medium

 · Overview: what are the basic components, observational overview. the major ISM surveys. gas structures. HI distribution. GMCs, clumps, cores. HII regions of different kinds and Reynolds layer. ISM components  · HII regions basics: photoionization balance. Stromgren spheres w and w/o dust, mass of ionized gas vs. density. Ionization fronts. heating/cooling/temperature, recombination lines (Case B theory, fundamental recomb line ratios, how they are calculated and where to find them), fine structure lines and n,T diagnostic line ratios, calculation of emitted spectra. planetary nebulae. abundances. How to get Nlyc from H lines, bremsstrahlung. close association of mid-IR and radio continuum in HII regions.  · atomic H basics: 21 cm line, spin temperature and excitation, how to obtain column densities. Lilly’s law. the two components of HI (Radakrishnan result)  · molecular gas basics. H2, energy levels, lines, where seen and excitation. (this presumes a basic understanding of molecular vibration-rotation spectra). tracer lines, critical density. LVG models. basics of cosmic chemistry and fractionation. CO conversion factor and evidence behind it. how to get column densities from an optically thin line, partition functions.  · PDRs, XDRs basics (molecular counterpart to HII regions). structure and chemistry. PAHs. H2 lines.  · dust: dust is probably covered elsewhere, but links to gas, gas temperature.  · SNR. spectra. standard theory of SNR evolution (including shocks & blast waves).  · magnetic fields. the observed B field properties, basic B field strengths. how to measure B fields. rotation measure, dispersion measure, minimum energy field.  · two phase model.  · star formation: there are aspects of this probably covered elsewhere, but here cores, association with IR sources, efficiencies, starless cores, internal support of cores. chemical structures of PPDs, chemistry and star formation.
 * The Interstellar Medium **