Events at Physics |
Events on Tuesday, February 24th, 2015
- Chaos & Complex Systems Seminar
- Sweet talks and trade deals in symbiotic associations
- Time: 12:05 pm - 1:00 pm
- Place: 4274 Chamberlin Hall (Refreshments will be served)
- Speaker: Jean-Michel Ané, UW Department of Agronomy
- Abstract: Living organisms, such as plants, animals and humans in particular, interact constantly with microbes present in their environment to form symbioses. These symbioses are very dynamic and can range all along a continuum between mutually beneficial interactions to parasitic ones. Sometimes, these associations are necessary for the survival of one or both partners, but they can also be facultative. These associations can be lost or acquired over time depending on environmental constraints. We will discuss how plants and microbes communicate (sweet talks) to initiate and maintain symbiotic associations, how these mechanisms evolved or have been lost sometimes, but also how nutrients exchanges between partners are regulated with interesting similarities to economic markets (trade deals).
- Host: Clint Sprott
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Faculty Candidate Seminar
- The Discovery of Fermi Bubbles and Future Gamma-ray Telescopes
- Time: 4:00 pm - 5:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Meng Su, MIT, Joint MIT Pappalardo and NASA Einstein Fellow
- Abstract: The Fermi Bubbles are a pair of giant lobes at the heart of the Milky Way, extending roughly 50 degrees north and south of the Galactic Center, and emitting photons with energies up to 100 GeV. This previously unknown structure could be evidence for past activity of the central supermassive black hole. I will first summarize what we have learned about the bubbles through multi-wavelength observations and numerical simulations. We discovered the bubbles while searching for potential signal of dark matter particle annihilation toward the Galactic Center, using data from the Fermi Gamma-ray Space Telescope. More than six years successful operation of Fermi has proved the great potential of studying astrophysics, cosmology, and fundamental physics through gamma-ray sky. I will highlight the search of dark matter particles using gamma-ray and cosmic-ray observations, which motivated three future space telescopes: DAMPE, HERD, and PANGU. Together with the next generation ground-based Cherenkov telescopes e.g. CTA and LHAASO, we will be able to measure gamma-ray photons with energies from MeV to above PeV with much improved sensitivity. Finally, I will comment on a future plan to search for primordial gravitational waves produced from inflation in the very beginning of the Universe.
- Host: Dasu