Physics Department Colloquia
Events on Friday, December 15th, 2017
- The Missing Metals in the Universe
- Time: 3:30 pm
- Place: 2241 Chamberbelin
- Speaker: Joel Bregman, Univ. Michigan - Ann Arbor
- Abstract: After the Big Bang nucleosynthesis period, H and He were present, but not significant amounts of heavier materials, such as C, N, O, Si, Fe, or Pb. These heavier elements, known collectively as “metals” to astronomers, were produced by several types of stars and stellar events, including low and high mass supernovae and the merger of neutron stars (kilonovae). The cosmic mass density of such metals is inferred from direct observations of supernovae and from the cosmic history of star formation. Previous observations to detect these metals in the local Universe find that 70-90% are unaccounted for (“missing metals”). This missing metals problem can be resolved if most of the metals lie in hot dilute gas surrounding galaxies and in the cosmic web. We discuss the detection of these metals in hot environments using X-ray astronomy and the tools needed for future observations.
- Host: McCammon