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Discover the Milky Way's rotation curves and dark matter candidates, with insights into gravitational microlensing and neutrinos. Learn about cosmic acceleration, dark energy, and the future of the Universe.
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21 cm Radiation as Tracer of Gas Clouds 21 cm map of our Galaxy
Microlensing Targets Large Magellanic Cloud Small Magellanic Cloud
Neutrinos as Nonbaryonic Dark Matter About 100 neutrinos per cubic cm, throughout space. Mass is about 0.05 eV = 1 / 10,000,000 mass of electron, although some uncertainty. Neutrinos in the Universe have nearly as much mass as all of the stars! Superkamiokande, an Example of a Neutrino Observatory
Other Types of NonbaryonicDark Matter XENON Dark Matter Detector
Large Hadron Collider at CERN The LHC will search for supersymmetric and other new subatomic particles.
Dark Matter in Other Spiral Galaxies – Flat Rotation Curves NGC 3198
Dark Matter in Elliptical Galaxies – Evidence from X-ray Gas NGC 4697 optical NGC 4697 Chandra
Dark Matter in Clusters of Galaxies The Coma Cluster Fritz Zwicky
Galaxy Motions in a Cluster of Galaxies The Coma Cluster
X-ray Evidence for Dark Matter in Clusters of Galaxies Need enough gravity to keep the X-ray gas from “boiling off” into intergalactic space.
Gravitational Lensing Evidence for Dark Matter in Clusters of Galaxies
The Acceleration of the Universe Examples of type 1a supernovae Thermonuclear detonation of white dwarf High-redshift supernovae are systematically fainter than expected based on extrapolation of low-redshift sources. Must be further away than expected. So need an effect to overcome the tendency of gravity to slow down the expansion.
Dark Energy in the Universe Cosmic acceleration suggests presence of “dark energy” that drives space apart. This “dark energy” dominates the mass-energy density of the Universe! Supporting evidence comes from studies of the cosmic microwave background, clusters of galaxies, and large-scale structure. What is this “dark energy”? Why is there the observed amount, not much more or much less?
The Future of the Universe We cannot predict the fate of the Universe until we understand dark energy.