Jamila’s Title: Finding low SNR exoplanets in data with complete signal models

Abstract: Exoplanet signals in data are masked by complex instrumental noise and astrophysical sources of apriori unknown form. Traditional detection pipelines rely on sequential data processing with incomplete signal models at each step, which can lead to overfitting and reduced detection sensitivity for faint exoplanetary signals. In this talk, I will first describe my work on robust data-driven signal models and tractable joint-modeling approaches to improve the detection of weak exoplanet signals in transit light curves. These new joint-modelling approaches were used to search Kepler/TESS data and have so far uncovered 16 new data-rich exoplanet candidates.
Anticipating future missions to directly image exoplanets with Earth-Sun sensitivities, the second half of this talk will focus on optical modeling of starshades. Here I will present my work on developing tractable optical simulation techniques, which I use to study the performance of starshades in the context of realistic astrophysical scenes. Broadly, this work aims to assess the utility of starshades in preparation for HWO.


Fan’s Title: How do supermassive black holes grow from z = 4 to z = 0?

Abstract: Supermassive black holes (SMBHs) grow together with their host galaxies throughout cosmic time, and two growth channels are present – accretion and merger. I will talk about our recent efforts to build a complete picture of the SMBH growth under these two channels. Regarding the accretion channel, the population mean SMBH accretion rate primarily correlates with galaxy stellar mass and redshift for the general galaxy population. I will present the survey data preparations briefly and the best measurements of this function, where we use X-rays to sample the AGN accretion power and multiwavelength surveys to sample galaxies. I will then combine our observed accretion with modern cosmological simulations, which provide merger information, to illustrate how SMBHs evolve from z = 4 to z = 0. Our analyses can predict multiple properties of the SMBH population, such as their mass function, their scaling relation with their host stellar mass, and the contributions of the two growth channels to the overall SMBH population growth.