Overview of ISM
Phases, properties of gas and dust, distribution of ISM
Observing the ISM
Techniques available at all wavelengths
Ionization
Photoionization & recombination of hydrogen and other
elements, HII regions, Stromgren spheres, partially
ionized regions, collisional ionization.
Recombination Radiation
Visible & radio recombination lines of hydrogen and
other elements, free-free radiation, bound-free
radiation. Determining properties of HII regions from
radio continuum data
Forbidden line Emission
Multi-electron ions, collisional excitation, determining
temperatures, densities and abundances in HII regions,
thermal balance in HII regions
The 21-cm line
Basic radio astronomy, emission and absorption, ,
rotation curves of the Galaxy, kinematic distances,
measuring masses of HI in galaxies. estimating gas
temperatures, introduction to phases of ISM.
Interstellar chemistry Molecular hydrogen, formation and destruction of
molecules grain surface and gas phase chemistry, PAH
molecules.
Absorption and emission from molecular
gas Observations of mm CO emission, optical depth and
excitation effects, cloud models, LVG codes, use of
isotopes, high density tracers, determining physical
conditions in clouds. Typical properties of molecular
clouds. Interstellar masers.
Interstellar extinction Dust extinction, reddening, IR and UV properties,
scattering and albedo, exceptions to thin-screen model,
gas-dust correlations, X-ray absorption. Polarization of
starlight
Radiation from dust Thermal equilibrium of dust grains, VSGs and PAH
emission. Lyman-alpha heating of dust within HII regions,
dust inside the Solar System.
The nature and evolution of dust grains Size of dust grains from extinction curve, Dust
spectral features, abundance considerations. Origin of
dust grains, carbon-rich and oxygen rich stars,
destruction processes, sputtering, interstellar grains
within the Solar System, interplanetary dust.
Interstellar Magnetism Nature of interstellar magnetic field, flux freezing,
ambipolar diffusion, Zeeman effect, Alfven waves,
interstellar polarization.
Shock Waves Sound speed, jump conditions, ionization fronts,
radiation from shocks, Coronal lines, X-ray emission. IR
molecular hydrogen emission
Cosmic Rays Energy spectra, composition, propagation, scattering,
lifetime in Galaxy, gamma ray production,
Synchrotron radiation. Single particle radiation, power laws, polarization,
energy losses, self-absorption, supernova remnants,
galactic background
Radio Propagation through ISM Plasma frequency, low frequency absorption, pulsar
dispersion, Faraday rotation, Faraday depolarization,
interstellar scintillation
Heating, cooling and phases of ISM Cooling processes in molecular, atomic and ionized
gas, Heating processes, pressure balance, thermal
instabilities, shock heated gas, models for interstellar
clouds, photo-dissociation regions.
Galactic Distribution of interstellar
gas Scale heights, Oort limit, thickness of gas
distributions in the Galaxy, large-scale structure of HI,
distribution of molecular clouds, spiral arms, diffuse
ionized gas, gas in the halo, high velocity clouds,
Galactic Center.
Interstellar matter near the Sun Local bubble, interplanetary medium, solar wind,
heliopause, Lyman-alpha backscattering, helium wake.
Gravity and Stability Jeans length, fragmentation, Parker instability,
stability of molecular clouds, virial mass, spherical
collapse, rotation, formation of disks
Star forming regions Molecular cores, low mass star formation, bipolar
flows, clustering, high mass star formation, triggered
star formation.
Origin and fate of interstellar matter Mass loss stars, planetary nebulae, Supernovae,
evolution and balance of interstellar medium
Interstellar gas in other galaxies
ISM in Ellipticals. Differences in spiral gas content
along Hubble sequence. Starbursts, AGNs. Emission line
diagnostics