POLSTAR Survey: Magnetic Fields in Star Forming Filaments

Polarized thermal emission from spinning dust grains that align themselves with the magnetic field can be used to trace the magnetic field structure projected onto the plane of the sky. With powerful polarimeters on new facilities, the window to the polarized sky is just opening up now. This makes a systematic investigation into magnetic fields in galaxies a very timely project. This investigator created the POLSTAR survey of selected star forming regions in the Milky Way. Her team is combining existing images with new observations of the polarization properties of these objects. With POLSTAR, the team has capitalized on this technical progress to acquire a unique and comprehensive data set of polarized dust and line emission on several world class telescopes to develop a comprehensive vision of the magnetized dense interstellar medium. The investigator’s work aims to clarify how magnetic fields affect star formation in high-mass dense filamentary dark clouds and how the fields change when stars form. Through this award, a graduate student will be trained, and several high-school minority students will have the opportunity to work with astronomical data visualization and analysis tools. Using POLSTAR data investigators team will provide the most comprehensive multi-wavelength overview of the role of magnetic fields in forming high-mass dark clouds and stars within them. They seek to understand the evolution of a high-mass dark clouds and how magnetic fields change the star formation process. The magnetic fields are thought to slow down star formation and the team will measure the density threshold where the fields give way to gravity. Analysis of the multi-wavelength multi-scale polarization data will be crucial to constrain theories on how spinning dust grains align. In conjunction with mock observations using advanced simulations of clouds with different input magnetic field strengths, this project will provide images of the initial conditions for star-formation in an important sample of Milky Way Clouds. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.