Western Kentucky University
Seeing the Spiral from the Arms: Modeling the Interstellar Medium of the Milky Way
Institution
Western Kentucky University
Faculty Advisor/ Mentor
Steven Gibson
Abstract
Our home galaxy, the Milky Way, has been a focus of astrophysical research since before we knew there were other galaxies in the universe, but in a number of ways it remains mysterious. The exact size and spiral arm structure of the Milky Way are still poorly understood. Observations have been instrumental in uncovering what we do know about our galaxy, but theoretical models interpreting these results are also crucial. Our model tests possible relationships between different kinds of interstellar gas observed with radio telescopes. We have run a series of models with cold atomic gas and colder molecules in different parts of the spiral arms embedded in a warmer atomic medium. Our goal is to determine how gas that is compressed and cooled upon entering spiral arms – precondition for star formation -- would appear in radio surveys. We have also created progressively higher resolution models that reproduce sections of the galaxy in greater detail to examine individual interstellar clouds. We have assembled ``cubes'' from stacked individual model images to allow enhanced visualization and analysis of the model predictions. Ultimately these model results relate to larger issues of galactic structure and stellar evolution in the Milky Way and galaxies like it.
Seeing the Spiral from the Arms: Modeling the Interstellar Medium of the Milky Way
Our home galaxy, the Milky Way, has been a focus of astrophysical research since before we knew there were other galaxies in the universe, but in a number of ways it remains mysterious. The exact size and spiral arm structure of the Milky Way are still poorly understood. Observations have been instrumental in uncovering what we do know about our galaxy, but theoretical models interpreting these results are also crucial. Our model tests possible relationships between different kinds of interstellar gas observed with radio telescopes. We have run a series of models with cold atomic gas and colder molecules in different parts of the spiral arms embedded in a warmer atomic medium. Our goal is to determine how gas that is compressed and cooled upon entering spiral arms – precondition for star formation -- would appear in radio surveys. We have also created progressively higher resolution models that reproduce sections of the galaxy in greater detail to examine individual interstellar clouds. We have assembled ``cubes'' from stacked individual model images to allow enhanced visualization and analysis of the model predictions. Ultimately these model results relate to larger issues of galactic structure and stellar evolution in the Milky Way and galaxies like it.