Preliminary Exam |
Events During the Week of November 16th through November 22nd, 2025
Monday, November 17th, 2025
- No events scheduled
Tuesday, November 18th, 2025
- No events scheduled
Wednesday, November 19th, 2025
- Searches for High-energy Neutrinos Accompanying Astrophysical Transients
- Time: 11:00 am - 1:00 pm
- Place: Chamberlin Hall Room 5310
- Speaker: Alicia Mand
- Abstract: Multi-messenger astronomy enables us to probe extreme astrophysical phenomena in new ways. In particular, astrophysical neutrinos reveal information that is not available via any other messenger. Neutrinos are the “smoking gun” signature for hadronic processes – meaning that identification of neutrino sources can elucidate the origins of high-energy cosmic rays. Multiple observatories, such as the IceCube Neutrino Observatory and KM3NeT, are currently collecting data on astrophysical neutrinos. The first detection of high-energy astrophysical neutrinos was reported in 2013 by the IceCube collaboration. However, despite detecting astrophysical neutrinos for over a decade, the sources of these neutrinos are still largely unknown, despite thorough searches. I will present results and work in progress from three such searches using data from the IceCube Neutrino Observatory. The first is a search for neutrinos from SN 2023ixf, the closest and brightest core-collapse supernova in the last decade. The second is a follow-up of the highest-energy neutrino ever detected, measured by KM3NeT to have energy approximately 200 PeV, to search for additional neutrinos from the same direction that could help determine its origin. Finally, I will present a search under development for neutrinos in the directions of fast radio bursts (FRBs) detected by the CHIME telescope.
- Host: Justin Vandenbroucke
Thursday, November 20th, 2025
- No events scheduled
Friday, November 21st, 2025
- Measuring the Flavor Composition of the Cosmic Neutrino Flux at High Energies with IceCube
- Time: 10:00 am - 12:00 pm
- Place: Chamberlin Hall Room 5280
- Speaker: Hannah Erpenbeck
- Abstract: The IceCube Neutrino Observatory detects neutrinos by instrumenting 1 km3 of deep glacial ice with photomultiplier tubes. These detections allow for the study of possible astrophysical neutrino sources and the measurement of the diffuse astrophysical neutrino flux. The flavor composition of the measured flux is a very important component in understanding and modeling the astrophysical neutrino flux. In addition, an improved measurement of the flavor composition of the astrophysical neutrino flux at Earth allows us to infer the flavor composition at the sources and thus provides insights into neutrino production mechanisms. I will present the plan for a new flavor analysis using a combination of datasets used within the IceCube Collaboration. Previous flavor measurements with IceCube focused on individual samples targeting distinct event types, mostly dominated by events with interaction vertices inside the detector. Building on existing efforts, I plan to perform such a measurement on an expanded dataset. Such a sample includes contained and uncontained events, incorporates improved ice modeling, and achieves the highest statistics for the high-energy neutrino flux. These updates in event classification promise improvement in the sensitivity of the flavor measurement. Identifying double-cascades among tracks and cascades is a continuous effort, and the main focus of my talk.
- Host: Albrecht Karle