Main Colloquium
Dr. Timothy Davies	SCHEDULED

Cardiff University

In this talk I will describe how mapping the dynamics of gas clouds in the centre of galaxies can help us to constrain a wide range of astrophysical problems. From the enigmatic relation between galaxies and their supermassive black holes, to the suppression of star-formation in dying galaxies, the dynamics of cold gas provides an ideal probe that can help us make progress. I will show how parsec resolution ALMA observations can be used to estimate the masses of supermassive black holes in galaxies across the Hubble sequence, both dynamically, and via the newly discovered ‘fundamental plane of black hole accretion in the millimetre”. I will describe the WISDOM and WONDER projects, that aims to use this technique to constrain the importance of accreting SMBHs in galaxy quenching. I will go on to show that, contrary to expectations, molecular gas appears to be an important source of fuel for accretion in even low-luminosity, low-excitation active SMBHs. Finally, I will show that the deep potential wells of massive galaxies change the small-scale structure of the ISM, suppressing star formation, and helping to keep bulge-dominated objects quenched.

	Special Colloquium
Erandi Chavez	SCHEDULED

Center for Astrophysics

Does the supermassive black hole at the center of our galaxy, Sagittarius A* (Sgr A*), have a jet? Results from Event Horizon Telescope (EHT) data favor accretion flow models in which one is present, however, it has not been conclusively detected. Using simulated data based on the 2017 EHT best-best models of Sgr A*, we explore the possibility of detecting this jet with existing and next-generation VLBI arrays at 86, 115, 230, and 345 GHz. The competing astrophysical effects of jet power, jet variability, and interstellar scattering due to ionized plasma between Earth and the Galactic Center add complexity to the prospects for jet recovery in images of Sgr A*. In addition, the VLBI arrays we consider have different array configurations and instrument sensitivities that significantly influence their ability to image the jet. While current VLBI arrays are unable to capture the jet, next-generation arrays at 86 and 115 GHz such as the ngVLA and the next-generation EHT are able to image the jet. The prospects towards detecting a jet in Sgr A* are bright and motivate the continued development of these next-generation radio observatories.