Abstract:
Recent evidence suggests a correlation between spiral arm pitch angle and
supermassive black hole (SMBH) mass. We use an improved method to accurately
measure the spiral arm pitch angle in disk galaxies to generate quantitative
data on this morphological feature for 34 galaxies with directly measured
black hole masses. This method is compared with other means of estimating
black hole mass to determine its effectiveness and usefulness relative to
other existing relations. Such a relationship is predicted by leading theories
of spiral structure in disk galaxies, including the density wave theory. We
propose this relationship as a tool for estimating SMBH masses in disk
galaxies, and have used this relation to construct a SMBH mass function for
disk galaxies in the local universe.