Preliminary Exam |
Events During the Week of November 26th through December 3rd, 2023
Monday, November 27th, 2023
- No events scheduled
Tuesday, November 28th, 2023
- Finding Radio-Loud Strong Gravitational Lenses Using Large Surveys
- Time: 2:30 pm - 6:00 pm
- Place: B343 Sterling
- Speaker: Michael Martinez, Physics PhD Graduate Student
- Abstract: Strong Gravitational Lensing, the phenomenon by which a background source is magnified and split into multiple images by a massive foreground object, is one of the most versatile tools to modern astrophysicists, with applications to everything from studying high-redshift galaxy evolution to measuring the Hubble Constant. As lensing is sensitive to all mass along the line of sight from the lensed source to the Earth, it offers sensitivity to dark matter halos even if no luminous stellar population is present. Radio wavelength Very Long Baseline Interferometry (VLBI) observations, which provide milliarcsecond resolution and complement existing optical and infrared studies, are ideal for measuring the perturbations caused by these low-mass halos. In this talk, I present the results of a pilot project to discover new radio-loud gravitationally lensed sources. Using Very Large Array (VLA) follow-up to VLA Sky Survey (VLASS) selected lens candidates, we report 5 new radio-loud gravitational lenses, a 10% increase in the present sample size. I will also discuss plans for future observations in which we expect to further extend this sample by 50%, laying the groundwork for a statistically robust VLBI program to provide new constraints on dark matter.
- Host: Keith Bechtol
Wednesday, November 29th, 2023
- PeV Neutrino Astronomy with IceCube
- Time: 1:45 pm - 3:45 pm
- Place: B343 Sterling
- Speaker: Emre B. Yildizci, Physics PhD Graduate Student
- Abstract: In the past, Icecube diffuse neutrino analyses at high energies have utilized event selections with contained and non-contained vertices separately. I have started to investigate the possibility of a unified, combined analysis approach. This approach promises a significant enhancement in selection efficiency for the highest-energy neutrinos. Additionally, I have studied novel techniques to reject background from cosmic ray muons. I will present our initial findings and the plan for completing the analysis.
- Host: Lu Lu
Thursday, November 30th, 2023
- No events scheduled
Friday, December 1st, 2023
- No events scheduled