AST 6336

Interstellar Matter

Spring 2005



The course covers the following topics:

  1. Observational sketch of the interstellar medium (ISM): entities(H II regions, planetary nebulae, nova shells, supernova remnants), spectra (optical, radio, IR, UV, XR)
  2. Thermodynamic equilibrium: strict TE, local TE, equivalent TE, statistical equilibrium and cyclic processes in general
  3. Simple model of an H II region: the Strömgren sphere; ionization stratification
  4. Ionization structure of planetary nebulae and chemical composition effects
  5. Recombination spectrum of H II regions and planetary nebulae: photoionization and recombination, Baker-Menzel cases; free-free radiation; two-photon emission; radio recombination lines
  6. Collisional processes and "forbidden" lines; Bowen mechanism
  7. Radiation from nova shells and from supernova remnants, including synchrotron radiation
  8. Estimates of Te and Ne, chemical composition in gaseous nebulae from line data
  9. Interstellar absorption lines, doublet-ratio method
  10. 21-cm line of H I in emission and absorption; molecular radio lines, masering
  11. Interstellar dust: grain sizes and characteristics; grain formation and destruction
  12. Interstellar magnetic field, Faraday rotation
  13. Heating vs. cooling in the ISM; equilibrium temperatures
  14. Gas dynamics, with emphasis on shock waves; ionization fronts; instabilities; similarity solutions
  15. Evolution of H II regions, planetary nebulae, and supernova remnants
  16. Star formation, scenarios
  17. Models of the ISM


There will be three hour examinations, essentially non-cumulative, scheduled for the following dates: Feb. 3, Mar. 17, and Apr. 14. In addition there will be a few very brief unannounced quizzes on recently-covered material from time to time. Also, a few problems will be assigned. The final examination, which is cumulative, is scheduled for Wed., Apr. 27 at 7:30 am. (Needless to say, we will want to have a discussion concerning a mutually agreeable alternate time such as, say, Tues. Apr. 26 at 10:00 am.) The course grade will be the weighted sum of the average grades on hour examinations, quizzes, and problems and the grade on the final examination, as:

C=0.3 F + 0.5 H + 0.1 Q + 0.1 P

where C is the course grade, F is the grade on the final examination, H is the average of the grades on the hour tests, Q is the average of the grades on the unannounced quizzes, and P is the average of the grades on the problems. The grade scale is

A=90-100

B+=85-89

B=80-84

C+=75-79

C=70-74



My office hours are MWF 4 or by appointment. You may reach me by e-mail at hsmith@astro.ufl.edu

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