Quiz 05/09/13

1. What do we mean by dark matter and dark energy? Dark matter is the name given to the unseen mass whose gravity governs that observed motions of stars and gas clouds. 
2. What is the evidence for dark matter in galaxies? Orbital velocities within galaxies remain nearly constant at large radii, indicating that most of the matter lies outside the visible regions.
3. What is the evidence for dark matter in clusters of galaxies? Masses measured from galaxy motions, temperature of hot gas, and gravitational lensing all indicate that the vast majority of matter in clusters is dark.
4. Does dark matter really exist? Yes
5. What might dark matter be made of? Nonbaryonic particles
6. What is the role of dark matter in galaxy formation? The gravity of dark matter seems to be what draws gas together into protogalactic clouds, initiating the process of galaxy formation.
7. What are the largest structures in the universe? Galaxies
8. Who was Fritz Zwicky? He was a swiss astronomer. He made many important contributions in theoretical and observational astronomy.
9. Who is Vera Rubin? Vera Cooper Rubin is an American astronomer. In 1951, she completed her education and she made one of the first observations and deviations from the Hubble flow in the motions of galaxies.
10. Who is Alex Filippenko? Alex Filippenko is an American astrophysicist and professor of astronomy at the University of California, Berkeley. His research focuses on supernovae and active galaxies at optical, ultraviolet, and near-infrared wavelengths.