An evolving cosmic mystery
with Casey Law
Sat February 18 – 11am
Campbell Hall Room 131, UC Berkeley
Campbell Hall is on Upper campus. If coming by BART, allow 15-20 minutes to walk up the hill from our usual venues. Nearby public parking is available in the Upper Hearst Structure on Hearst and Gayley. Accessible spaces are available on University Drive near Campbell Hall.
Ten years ago, astronomers discovered a brief and surprisingly bright blast of radio waves that appeared to come from far outside our galaxy. The naive interpretation of that burst argued for a new class of extragalactic object called a “Fast Radio Burst” (FRB). The problem was that the apparent distance of the FRB meant that it was far more powerful than any known radio transient. Could it be a truly new object, such as a cosmic string or an as-yet unseen class of compact object? Or could we be fooled by something more ordinary, such as a microwave oven on the Earth? After that discovery, another 20 FRBs were detected at telescopes around the world, but we still did not know their distance, intrinsic power, or what could generate them.
Casey will present the rapidly evolving story of the FRB. His collaboration has used a new data-intensive technique with the Very Large Array to directly image an FRB burst and measure its distance for the first time. The last decade of study of FRBs offers a rare example of how science deals with new phenomena and adapts to new problems. Happily, the measurement of an FRB distance does not end this story, but instead it opens a host of new ideas and avenues for exploration.
Casey’s research currently focuses on developing radio interferometers in the study of fast (subsecond) transients. Transients on this time scale are typically observed with large, single-dish radio telescopes or phased interferometers. My work is different in that I use the raw product of an interfermeter (visibilities) to search for fast transients. This effectively makes interferometers into high speed cameras that can find and localize radio transients over a wide field of view.
This free public talk is presented as part of the monthly “Science@Cal Lecture Series”
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