Hannah Sousa-Fronenberg & Jillian Rastenejad

Talk 1: Hannah Fronenberg, 3:00pm -  3:30pm
Can cross-correlations deliver measurements of the Epoch of Reionization?
21cm observations have the potential to directly probe the epoch of reionization, but significant observational challenges remain. Foreground contamination and instrument systematics can in principle be mitigated through cross-correlations with other probes such as line intensity maps (LIM), but existing forecasts of such measurements generally do not include these detrimental effects. In order to perform and interpret cross-correlations in actuality, we need to better understand the role of various systematics. In this talk, I will present a novel end-to-end pipeline which takes into account foregrounds and instrumental effects in order to produce estimates on both the 21cm-LIM cross-spectrum and its errors. As a case study, cross-spectrum measurements of the 21 cm and [CII] lines observed by HERA and CCAT-prime respectively at 6 < z < 8 are presented. These lines are anti-correlated on scales larger than the bubble scale but positively correlated on smaller scales. Searching for the scale and evolution of this sign flip as a function of redshift can help constrain both the timing and morphology of reionization. Finally, I will conclude by highlighting the transformative potential of these synergistic measurements in constraining cosmology at high-redshift.

Talk 2: Jillian Rastenejad, 3:30pm -  4:00pm
Exploring the origins of r-process elements with GRBs
The landmark discovery of the first binary neutron star merger and its accompanying kilonova confirmed that these events are responsible for creating at least some of the Universe's r-process elements. Despite the treasure trove of data provided by this discovery, numerous unknowns remain about the origin of the Universe's heavy elements, including the median and span of kilonova yields and the existence of a secondary r-process production site. In this talk, I will discuss our work expanding our view of the diversity of kilonovae and their heavy element yields using observations following gamma-ray bursts (GRBs). I will also highlight our recent efforts to probe a favored secondary r-process production: the supernovae associated with GRBs.