This three-year award will support U.S.-France cooperative research in galactic astronomy involving Thomas Troland, University of Kentucky, Richard Crutcher, University of Illinois, and Ilya Kazes at the Observatoire de Meudon in France. The investigators propose to continue their successful research on magnetic field strengths in the evolution of interstellar clouds and star formation. Magnetic fields have emerged as a mechanism for explaining star formation and other cosmic phenomena. The only known technique for measuring magnetic field strength is detection of the Zeeman effect in radio frequency spectral lines. The U.S. and French investigators will continue their survey observations of the OH Zeeman effect of dark clouds using the VLA (Very Large Array), Green Bank and the Arecibo telescopes. They will extend their research to denser regions by observing the Zeeman effect in the 3-mm lines of CN using the IRAM 30-m telescope. This experiment will allow direct probing of magnetic fields at a crucial stage in star formation when core fragmentation and collapse are taking place. Observations with the IRAM telescope is essential since its collecting area is sizeable and will allow for observations in denser regions of space. The project will benefit from French expertise in observation and access to the IRAM facility in Europe. Through the observational program, the investigators will be able to test fundamental theories of magnetic fields in interstellar clouds and enhance our understanding of the role of magnetic fields in star formation.
