ARRA: Observations of Magnetic Fields in Molecular Clouds - Exploring Two Key Issues

Intellectual Merit This proposal seeks support for observational studies of the role of magnetic fields in star- forming regions of the Galaxy. In particular, I seek to answer two fundamental questions that have yet to be addressed by observations: (1) What is the role of the magnetic field in the evolution of molecular clouds as a whole? And (2) what is the role of the field in distinguishing between high and low-mass star formation? In order to answer these questions, 1 will use the Zeeman effect in 1665 and 1667 MEIz OH lines and in 113 GHz CN lines to measure field strengths directly in two types of regions: (1) the low density (inter-clump) regions of molecular clouds and (2) infrared dark clouds (IRDCs), believed to be the precursor regions to massive star formation. These measurements will allow me to determine the ratio of gravitational to magnetic energy (2) and the ratio of turbulent to magnetic energy (fi~b) in both types of regions. These ratios, now completely unknown from observations of such regions, determine the role of the magnetic field in molecular cloud evolution and, also, in high-mass star formation. I will conduct OH Zeeman observations at Arecibo and at Green Bank. I will conduct CN Zeeman observations with the IRAM 30 m telescope in Spain. Although this project is conceptually straightforward, it will require a large investment in telescope time to achieve the necessary sensitivities. However, my previous experience with all of these observatory facilities suggests that sufficient telescope time will be made available, given the significance of the expected results. Broader Impacts The research described in this proposal will have broader impacts upon society in two different ways. For one, I will mentor students at the University of Kentucky. These will include at least one graduate student and several undergraduates (the latter, during summers). The graduate student, I expect, will earn a Ph.D. as a result of work on this project and will be prepared for a professional career in astronomy. The undergraduate students, I hope, will gain valuable experience in astronomy research and insights into their future career interests. (A pivotal time in my career came during my undergraduate years when I participated in summer astronomy research. This experience, more than any course work, shaped my interest in astronomy and my future career in this field.) The other impact of my research comes through frequent astronomy outreach activities. For example, I have participated for many years in NSF sponsored K12 teacher professional development programs in Green Bank. I have participated in the last few years in a nationally organized classroom visitation program called Journey Through the Universe, visiting communities throughout the U.S. I frequently visit local K12 classrooms, and I give popular level astronomy presentations to community groups and to audiences at regional colleges and universities. My legitimacy in these presentations, and the subjects I often highlight during them, come partly from my experience as an active researcher. Finally, I plan to reorganize and institutionalize my program of K 12 classroom visitations in my community. My goal is to create a sustainable program of classroom visitations, a program that addresses core astronomy concepts in the curricula for specific grade levels in Kentucky. This plan is described in the last section of the Project Description.