Physics Graduate Student Symposium | Supermassive Black Holes as the Regulators of Star Formation in Central Galaxies

Cavities and bubbles in the extended X-ray emission from massive galaxies demonstrate that feedback from supermassive black holes can have a profound effect on the hot gaseous atmospheres that surround these systems. The consequences of these effects result in dramatic changes with respect to how the baryon cycle works and whether new stars are able form within these galaxies. With this concern in mind, we present a relationship between the black hole mass, stellar mass, and star formation rate of a diverse group of 91 local galaxies with dynamically-measured black hole masses. For our sample of galaxies with a variety of morphologies and other galactic properties, we find that the specific star formation rate is a smoothly decreasing function of the ratio between black hole mass and stellar mass. With respect to galaxy formation models, our results present a powerful diagnostic with which to test various prescriptions of black hole feedback and its effects on star formation activity. Using the new IllustrisTNG simulation, we illuminate the physics behind quiescence in this model and compare with our observational results. We also use dozens of other TNG runs with varying physics implementations to show how observable galaxy trends and correlations are affected by changes in the black hole feedback physics, thereby providing a pathway to physically interpret observations.

Talks will be given each Wednesday and will be 30 minutes in length, with time after for questions. Lunch will be served at 11:45 and talks will begin at 12:00. Unless otherwise noted, they will be held in 340 West Hall.