Graduate Program Events |
Events on Wednesday, May 6th, 2026
- Academic Calendar
- Exams
- Abstract: *Note: actual end time may vary.* CONTACT: admin@secfac.wisc.edu
- Preliminary Exam
- Neutrino astronomy and oscillations with IceCube
- Time: 10:15 am - 12:15 pm
- Place: 5310 CH
- Speaker: Samyak Jain, Physics PhD Graduate Student
- Abstract: Neutrino astronomy continues to be a rapidly evolving field. In addition to identifying a handful of neutrino sources (NGC 1068, TXS 0506+056, and the Milky Way), the IceCube Neutrino Observatory has identified a diffuse flux of astrophysical neutrinos with unclear origins. Apart from astronomy, IceCube-DeepCore has also proved capable of placing leading constraints on neutrino oscillations. These oscillations may be modified by neutrino-matter interactions beyond the Standard Model - referred to as Non-Standard Interactions (NSI) - making IceCube potentially sensitive to them. In this talk, I will motivate Active Galactic Nuclei - which are promising sites of cosmic-ray acceleration - as significant contributors to the diffuse neutrino flux, and present IceCube-DeepCore’s sensitivity to NSI.
- Host: Francis Halzen and Dan Hooper
- Thesis Defense
- Identifying and Characterizing Dusty Star-forming Galaxies with ALMA and JWST
- Time: 2:00 pm - 4:00 pm
- Place: Chamberlin 5280
- Speaker: Stephen McKay
- Abstract: Understanding the formation and evolution of dusty star-forming galaxies (DSFGs) has been challenging due to the difficulty of reliably identifying them and determining their redshifts and physical properties. In my thesis, I present several studies using Atacama Large Millimeter/submillimeter Array (ALMA) and James Webb Space Telescope (JWST) observations to characterize the DSFG population. First, I use multiwavelength ALMA continuum observations of 870 μm-selected DSFGs to model their dust spectral energy distributions to high precision, showing that the dust properties of sources at cosmic noon are generally consistent with those seen in local galaxies and predicted by models. Second, I use a JWST/NIRCam selection to determine accurate positions for single-dish submillimeter (SCUBA-2) sources and to identify faint (S850μm < 2 mJy) DSFGs, enabling me to probe a lower star-formation rate (SFR) regime (SFR ~ 50-150 Msun/yr), below the typical limits of single-dish submillimeter surveys. I measure the physical properties and morphologies of these DSFGs, finding that the stellar masses and morphologies of the bright (S850μm > 2 mJy) sources are remarkably similar to those of the faint sources. I also observe a low fraction of major mergers in constrast with previous studies based on rest-frame optical wavelengths, suggesting that these studies may have been impacted by severe dust attenuation. Finally, I use ALMA linescans along with ancillary JWST and ground-based redshifts to achieve a nearly complete spectroscopic redshift distribution for a sample of DSFGs with S850μm > 2.5 mJy for the first time. I use these spectroscopic redshifts to test the effectiveness of various photometric redshift estimation methods and to constrain the shape of the DSFG redshift distribution.
- Host: Stephen McKay