Astrophysics Brown Bag Lunch Talk 11/15/2021: Speakers: Brenna Mockler (University Of California, Santa Cruz) And TK Chan (University Of Durham, UK)

Monday November 15, 2021 12:00 pm
TBA in person or via Zoom

Monday, November 15, 2021

12:00 – 12:30pm

Brenna Mockler, University of California, Santa Cruz

Snapshots of Black Holes in Action: probing supermassive black holes and galactic nuclei with tidal disruption events
Tidal disruption events (TDEs) provide an exciting opportunity to study supermassive black holes in quiescent galaxies and the stellar populations and dynamics in galactic nuclei. They regularly produce super-Eddington mass fallback rates, and their light curves encode information about the black hole mass. I developed the most widely used tool for measuring black hole masses with TDE light curves, however, it is difficult to measure the accretion efficiency and the mass of the disrupted star from the light curve alone. I will show how we can combine information from the TDE light curve with constraints from the spectra and host galaxy to learn about the properties of stars in galactic nuclei.
I am a finishing Ph.D. student in the Department of Astronomy & Astrophysics at UC Santa Cruz using high-energy transients to study the properties of supermassive black holes and galactic nuclei.  My Ph.D. research focuses on developing theoretical and numerical tools to study tidal disruption events and related transients such as changing look AGN, central-engine powered supernovae, and extreme mass-ratio inspiral mergers. I am also very committed to improving the culture in astrophysics and academia and have done significant outreach and mentoring related to this goal.


12:30 – 1:00pm

TK Chan, University of Durham, UK

Reionizing the Clumpy Intergalactic Medium

Reionization is an epic event when luminous sources ionized the neutral universe. The upcoming observations will reveal reionization in unprecedented detail, including its sources and geometry. However, the progress of reionization depended also on the sinks of ionizing photons: dense gas in the intergalactic medium (IGM) absorbs more photons due to fast recombination. Recent observations and simulations show the rapid evolution of the clumpy IGM during reionization. I will present my new, adaptive, and efficient radiative transfer method, SPH-M1RT. With this method, we simulate the complex interplay between the clumpy IGM and reionization. Finally, I will discuss the applications and developments of SPH-M1RT in galaxy simulations.

I am TK Chan, a post-doctoral research associate at Durham University. I develop numerical methods and run cosmological simulations to study how stars shape galaxies and their host dark matter halos. I also implement novel algorithms to make the models more realistic, e.g., by adding radiation and relativistic particles. Currently, I am studying the evolution of the intergalactic medium during the epoch of reionization. I am also coupling my radiative transfer scheme to galaxy simulations with resolved ISM physics.


Event Contact

Josh Borrow