Ph.D., Physics, University of Iowa 1975
Department of Physics and Astronomy
University of Iowa, 705 Van Allen Hall
Phone: 319-335-1948, FAX: 319-335-1753
Email: steven-spangler [at] uiowa.edu
Home page: http://www.physics.uiowa.edu/~srs
B.S., Physics, University of Iowa, 1972
M.S. Astronomy, University of Iowa, 1972
Ph.D. Physics, University of Iowa, 1975
My primary scientific interests are in the application of plasma physics to astronomy, as well as basic plasma physics. One area I find particularly intriguing is the solar corona. The main question about the corona is why it has a temperature of 1 million to 2 million degrees Kelvin, while the part of the Sun that produces visible sunlight (the photosphere) has a temperature of about 6000 Kelvin. Whatever the answer, and there have been many suggestions, it involves processes from plasma physics. My research activity concentrates on measuring properties of the coronal plasma such as the form of the magnetic field, the density of the gas, and the properties of the turbulence that exist there.
Another topic in astronomy that attracts my interest is the interstellar medium, or gas in the space between the stars. Some parts or ``phases'' of the interstellar medium are directly involved in the production of new stars. Other phases fill most of the volume of our galaxy, and are less dense, hotter, and more completely ionized. I am interested in measuring basic plasma properties of the interstellar medium. Many of the questions which arise are physically similar to those which arise in study of the solar corona, and we think that many of the same basic physical processes may be operative.
My favorite observational technique is radio astronomy. I have been making radioastronomical observations for 40 years, and have done so with many radio telescopes in the US and Europe. The main instruments I use in the research described above are the Very Large Array, and Very Long Baseline Array, both operated by the National Radio Astronomy Observatory. I love radio telescopes, and believe the study of how they work is every bit as interesting as the science we do with them. I enjoy involving students in all aspects of my research programs.
Finally, I am interesting in everything within the field of astronomy. If a topic is discussed in Sky and Telescope magazine, I am interested in it. I have a number of ``hobby interests'' in astronomy, in which I remain familiar with the literature, although I have not done any original research (yet). One of my favorites is ``solar analogs'', or stars similar to the Sun.
Haverkorn, M. and Spangler, S.R., Plasma Diagnostics of the Interstellar Medium with Radio Astronomy, Space Science Reviews 2013, 178, 483
Kooi, J.E., Fischer, P.D., Buffo, J.J, and Spangler, S.R., Measurements of Coronal Faraday Rotation at 4.6 Solar Radii, submitted to Astrophysical Journal, arXiv:1307.1727
Savage, A.H., Spangler, S.R., and Fischer, P., 2013, Probing the Rosette Nebula Stellar Bubble with Faraday Rotation, Astrophysical Journal, 765, 2013
Spangler, S. R., Savage, A.H., , and Redfield, S. 2011, Properties of Turbulence in the Very Local Interstellar Medium, Astrophysical Journal 742, 30, 2011
Spangler, S.R. 2010, Observational Tests of the Properties of Turbulence in the Very Local Interstellar Medium, Nonlinear Processes in Geophysics, 17, 785.
Spangler, S.R. 2009, Joule Heating and Anomalous Resistivity in the Solar Corona, Nonlinear Processes in Geophysics, 16, 443.
Whiting, C.A., Spangler. S.R., Ingleby, L.D., and Haffner, L.M. 2009, Confirmation of a Faraday Rotation Measure Anomaly in Cygnus, Astrophysical Journal, 694, 1452.
Spangler. S.R. 2007, A Technique for Measuring Electrical Currents in the Solar Corona, ApJ, 670, 841.
Ingleby, L. D., Spangler, S.R. and Whiting, C.A. 2007, Probing the Large Scale Plasma Structure of the Solar Corona with Faraday Rotation, Astrophysical Journal, 668, 520.
Spangler, S. R. Kavars, D., Kortenkamp, Bondi, M. Mantovani, F., and Alef, W. 2002, Very Long Baseline Interferometer Measurements of Turbulence in the Inner Solar Wind'', Astronomy and Astrophysics, 384, 654