Many galaxies with erupting black holes are found ____.
a. in poor clusters with little intergalactic gas
b. isolated in space
c. in one of a pair of orbiting galaxies
d. very close to the Milky Way galaxy
e. in the Local Group
Question 2A continuous spectrum is produced by ____.
a. atoms that become ionized
b. electrons that transfer from a high energy level to a low energy level
c. electrons that transfer from a low energy level to a high energy level
d. the intensity of agitation of atoms in a hot gas
e. the motion of an object toward or away from the observer
Question 3Supermassive black holes erupt in ____.
a. any type of galaxy, and at random times
b. elliptical galaxies only, when the last of their gas and dust is consumed
c. galaxies that have been part of a collision or merger
d. spiral galaxies only, during a burst of star formation
e. irregular galaxies
Question 4Absorption lines are produced by ____.
a. atoms that become ionized
b. electrons that transfer from a high energy level to a low energy level
c. electrons that transfer from a low energy level to a high energy level
d. the intensity of agitation of atoms in a hot gas
e. the motion of an object toward or away from the observer
Question 5A supermassive black hole erupts when ____.
a. it collides with a neutron star
b. magnetic fields form tubes to channel the jets
c. the accretion disk tilts to a new angle
d. a sudden flood of matter flows inward producingan accretion disk
e. starburst events irradiate the accretion disk with new energy
Question 6Emission lines are produced by ____.
a. atoms that become ionized
b. electrons that transfer from a high energy level to a low energy level
c. electrons that transfer from a low energy level to a high energy level
d. the intensity of agitation of atoms in a hot gas
e. the motion of an object toward or away from the observer