Events at Physics |
Events on Friday, October 9th, 2026
- Preliminary Exam
- Hunting for Galactic PeVatrons with IceCube
- Time: 9:30 am - 11:30 am
- Place: 5310 Chamberlin
- Speaker: Leo Seen, Physics PhD Graduate Student
- Abstract: Detecting cosmic rays, photons, and neutrinos enables a multi-messenger approach to studying high-energy processes in the Milky Way. Recently, IceCube reported neutrino emission from the Milky Way at 5.7𝜎, hinting at potential contributions from individual sources. Theoretical sources within our Galaxy capable of accelerating cosmic rays up to peta-electronvolt (PeV) energies are known as Galactic PeVatrons. When cosmic rays interact within or near their source, they produce 𝛾-rays and neutrinos. In this presentation, I will motivate resolved 𝛾-ray sources as possible neutrino source candidates by introducing ReGal-𝛾, a neutrino source template generated by combining 𝛾-ray source catalogs spanning GeV-PeV energies. Additionally, I will present results from a search for neutrino counterparts to 𝛾-ray sources with photon emission exceeding 100 TeV using 13 years of IceCube data. Finally, I will discuss the prospects of differentiating the Galactic neutrino source flux from the Galactic diffuse component.
- Host: Ke Fang
- Physics Department Colloquium
- Mapping the Evolution of Planet-Forming Disks: From Global Gas Reservoirs to Inner Chemistry
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241 -
- Speaker: Ke (Coco) Zhang, University of Wisconsin-Madison
- Abstract: Protoplanetary disks are cradles of planet formation. These disks play a vital role in shaping fundamental properties of planetary systems, such as the number of rocky and giant planets, as well as the bulk compositions of planetary cores and primordial planetary atmospheres. Gas is the dominant mass constituent in protoplanetary disks, taking 99% of mass initially. Yet, it is still unclear how the gas mass evolves and what mechanism drives its evolution, which has become a major challenge in understanding planet formation processes. In this talk, I will discuss results from the ALMA survey of Gas Evolution in PROtoplanetary disk, AGE-PRO, an ALMA Cycle 8 large program. We collected and analyzed deep ALMA observations of a comprehensive sample of 30 disks throughout the typical disk lifetime. By combining AGE-PRO observations and state-of-the-art thermo-chemical models, we provide accurate gas mass and size measurements of these disks. I will discuss how our results are compared with predictions from two leading theories of disk evolution: Turbulent viscosity and Magneto-hydrodynamical disk winds. Finally, I will show the JWST MIRI observations of the same sample, which provides important insight into the chemical evolution in the inner few au region.
- Host: Ke Fang