When Spiral Nebulae Were First Discovered, Astronomers Quickly Identified Them

Q4: _ galaxies have star formation, but no

Q5: S0 galaxies have spiral arms, but little

Q6: Gentle tidal interactions are probably necessary to

Q7: A supermassive black hole in the center

Q8: The range of diameters and luminosities displayed

Q10: Briefly describe the characteristics of an elliptical

Q11: Galactic _ describes the process of a

Q12: The _ depend(s) on the assumption that

Q13: NASA's Hubble Deep Field images and GOODS

Q14: Discuss the discovery of galaxies, and the