Zoom Link (password 114038)

Title: Quasars in Cosmic Reionization: Environment and Impact

Abstract: The epoch of reionization (EoR) is when the first galaxies form and ionize the neutral gas in the intergalactic medium (IGM). Due to the vast distance, direct observations of EoR were limited until the past decade. Data from quasars, the brightest nontransient objects, have opened windows to study structure formation at the earliest stages. 

The regions around the quasars, called quasar proximity zones, are particularly exciting because they offer insights into a wide range of interesting physics. In this talk, I will first demonstrate how to interpret the Lyα spectra corresponding to quasar proximity zones. Then, I will show how to use absorption features to recover the density and further constrain cosmological parameters and quasar properties. 

I will also present my suite of quasar proximity zone simulations and show how galaxy formation is affected in this radiation-dominated environment. I will conclude with an outlook on synergizing JWST and ground-based observations of quasar proximity zones to advance our understanding of reionization.

Title: TBA

Abstract: TBA

Title: TBA

Abstract: TBA

Title: Hidden Engines: Uncovering the Workings of the Nearest Galaxy Center

Abstract: Centers of galaxies are some of the most extreme objects in our universe: They host starbursts and active supermassive black holes that can launch jets and winds far outside the compact galaxy nucleus. The effects of the interactions among stars, gas and black holes that occur here don’t just stay confined to these small regions; they have an outsized influence on the overall evolution of galaxies as a whole. 

At just 8.1 kpc away, the center of the Milky Way is unparalleled in its proximity, making it the best laboratory for detailed studies of the processes that govern and define galaxy nuclei. However, the galactic center also presents a big challenge for these studies: It is a relatively quiet environment. Few stars are forming in this region, and the black hole is not active. Clearly, it hasn’t always been this way: From the Fermi Bubbles to hundred-year old echoes of X-ray bursts, there are many relics of an active past in the center of our own Milky Way. 

We also know our galaxy center likely won’t stay quiet for long; it contains a sizable reservoir of molecular gas that is the fuel for future star formation and black hole accretion. In this talk, I will present the results of research following the gas and its properties from kiloparsec to sub-parsec scales to understand why the galactic center is so quiet right now and what the future holds. Finally, I will discuss ongoing work to increase the sample size of galaxy nuclei with parsec-scale gas measurements and what this means for putting the Galactic center in context with its more active neighbors