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Colloquium Schedule

Fall 2020

Note: talks this fall are remote - via Zoom - and are open to anyone in the Tri-Co community.

Pulsar Timing Arrays: The Next Window to Open on the Gravitational-Wave Universe

Chiara Mingarelli, University of Connecticut
Wed., Oct. 7, 2020, 4:30 PM Register to join via Zoom 

Galaxy mergers are a standard aspect of galaxy formation and evolution, and most (likely all) large galaxies contain supermassive black holes. As part of the merging process, the supermassive black holes should in-spiral together and eventually merge, generating a background of gravitational radiation in the nanohertz to microhertz regime.  An array of precisely timed pulsars spread across the sky can form a galactic-scale gravitational wave detector in the nanohertz band. I describe the current efforts to develop and extend the pulsar timing array concept, together with recent limits which have emerged from international efforts to constrain astrophysical phenomena at the heart of supermassive black hole mergers.

Superconducting nanowire single-photon detectors: physics and applications

Emma Wollman ('09), NASA Jet Propulsion Laboratory
Fri., Nov. 13, 2020, 1:30 PM - a video of the talk is now available

Superconducting nanowire single-photon detectors, or SNSPDs, are able to detect single photons at wavelengths from the UV to mid-IR. SNSPDs have demonstrated detection efficiencies over 95%, timing resolution below 10 ps, and dark count rates less than 1e-3 counts/s. These characteristics make SNSPDs the detector of choice for applications ranging from fundamental tests of quantum mechanics to deep space laser communication. In this talk, I’ll describe the operational principle of SNSPDs and give some examples of their applications. In particular, I’ll focus on the Jet Propulsion Laboratory’s development of SNSPD arrays for deep space optical communication and for mid-IR astronomy.