Wata Chanita Tubthong (Tufts University)

Small circumbinary planets are truly rarer than small single-star planets
All circumbinary planets (CBPs) confirmed up-to-date are gas giants. No circumbinary super Earth has been discovered, despite the super Earths making up ~80% of the planet population around single stars. This is owing to the inherently biased nature of the by-eye discoveries of CBPs. Understanding the population of super Earths (or the lack thereof) around binary stars would shed light into the formation and evolution of planetary systems in a completely different environment than ours. We applied STANLEY, an automated algorithm that employed an N-body simulation to account for TTV, to Kepler eclipsing binary light curves to search for small CBPs. For the first time, we are able to demonstrate that circumbinary super Earths are genuinely rarer than super Earths hosted by single stars.

Weizhe Liu (University of Arizona)​

Probing AGN Feedback in the Early Universe
AGN feedback through powerful outflows is deemed a critical component in modern galaxy evolution models, which may regulate supermassive black hole accretion, quench star formation, and shape the circumgalactic and intergalactic medium. However, the effectiveness of such feedback in the early universe is largely unconstrained. In this talk, I will describe our on-going effort to address this open issue with both z>5 quasars and nearby dwarf AGN. For quasars, I will present our discoveries of galaxy-scale outflow in one of the earliest quasars at z~7.5 and an enhanced detection rate of rapid outflows in a statistical sample of z>5 quasars unveiled by JWST spectroscopy. These outflows are in general energetic enough to affect the evolution of their host galaxies, and a significant portion of them are much more influential than those in similar quasars at lower redshifts. For dwarf AGN, I will highlight our investigations of AGN feedback in nearby dwarf galaxies through observations of rapid outflows and molecular gas content, which suggest that AGN feedback should not be overlooked in these dwarf systems. These results imply that AGN feedback could also shape the evolution of high-z galaxies with similar physical properties.