Postdoctoral Fellowship: AAPF: A Multi-Decade Statistical Analysis of Sagittarius A*'s Total Intensity and Polarimetric Variability at Radio and Submillimeter Frequencies

Joseph Michail is awarded an NSF Astronomy and Astrophysics Fellowship to carry out a program of research and education at the Harvard-Smithsonian Center for Astrophysics. Michail will use observations of the supermassive black hole at the center of the Milky Way Galaxy, Sagittarius A*, to statistically study its variability. Results from this study will improve our understanding of what powers this enigmatic source.

For the educational component of this project, Michail will develop modules for an ongoing yearly workshop focused on training users on the Submillimeter Array, a group of telescopes on the summit of Mauna Kea, and will mentor undergraduate and graduate students throughout their education.

Using new and archival observations of Sagittarius A* at radio and submillimeter frequencies, this project will yield the most comprehensive statistical analysis of its variability on minute- to decade-long timescales. To do this, the investigator will: (1) use radio and submillimeter total intensity observations to track its flux and spectral variability, (2) use submillimeter polarization observations to monitor its accretion rate, and (3) lead coordinated observations at radio wavelengths with yearly Event Horizon Telescope multiwavelength campaigns of Sagittarius A*.

The conclusions drawn from this study will complement the numerous statistical analyses at infrared and X-ray wavelengths.

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.