Astronomy Colloquia at Caltech for 2021-22
Colloquia are held every Wednesday during the academic year at 4pm in the Cahill Hameetman auditorium. Wine and cheese will be served in the Cahill Foyer from 5:00-5:30pm (pending COVID restrictions).
NOTE: DURING COVID-19 PANDEMIC, ASTRONOMY COLLOQUIUM WILL BE VIRTUAL.
In the past decade we have started to explore extragalactic and intergalactic space using millisecond-duration radio flashes called fast radio bursts (FRBs). These cosmological signals are surprisingly abundant: there is likely an FRB occurring somewhere on the sky at least once every minute. They are also unique probes of the otherwise invisible material between stars and galaxies. But what is producing them? Thanks to a new generation of wide-field radio telescopes, several FRBs per day are now being discovered. Novel high-time-resolution observations using radio interferometers are also pinpointing FRB locations and providing host galaxy associations. More than a decade since the discovery of the famous `Lorimer burst', we are making rapid progress in our understanding of the enigmatic FRB phenomenon. In this talk, I will review the status of the field and then focus on how observations with the European VLBI Network (EVN) and the Low-Frequency Array (LOFAR) are shedding light on the nature of FRB sources. These observations have provided broadband characterisation, milli-arcsecond localisations and nanosecond-resolution polarimetry to help decode the FRB source model and emission mechanism.
To view this talk on YouTube, please go to: https://www.youtube.com/playlist?list=PLb1880Rn0qkKzIavl-n_7RaMyDOiU9XHm