CAREER: Untangling the physics of the magnetic, multi-phase interstellar medium

The space between the stars is not empty: interstellar space is filled with diffuse gas and dust, and threaded by invisible magnetic fields. This material is the interstellar medium (ISM), the stuff out of which new stars are born. The ISM is a wonderful physics laboratory. It is sculpted by a rich array of physical processes, and so observations of the ISM can be used to decipher the poorly understood physics that governs the formation of stars and the evolution of gas in galaxies. Astronomers observe the ISM in many wavelengths of light. This proposal will develop novel tools to unlock the physical information encoded in those observations. This work will generate a new understanding of the gas, dust, and magnetic fields in our Milky Way galaxy. Because the ISM obscures our view of light from the very early universe, this work will also help clear the way for cosmological discovery. This proposal will also build tight links between cutting-edge research and education, impacting students from high school through graduate school. This project will 1) develop a suite of pedagogical Jupyter notebooks to enable active learning in graduate ISM education, 2) host a workshop on integrating computational tools into the classroom, and 3) develop a new dual-enrollment astrophysics course focused on modern approaches to data-driven inference, serving low-income high school students. This proposal will develop cutting-edge methodologies for physical inference with complex data. The researchers will pursue a new approach to determining the phase structure of interstellar gas, and therefore to understanding the evolution of gas in galaxies. This work will open new avenues of inquiry by building computational tools to compare data and numerical simulations in high-dimensional spaces, and will reveal new insights into the magnetic structure of the ISM. This work will also build a new approach to modeling the structure of polarized dust emission from our Galaxy. This project also aims to realize the promise of the ISM for teaching and learning the universe. 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.