All of the following observations are real. Which one does not support the theory that active galactic nuclei are powered by accretion disks around massive black holes?
A) X-ray emission from active galactic nuclei can vary significantly in times as short as a few days.
B) The total luminosity of an active galactic nucleus can be as high as about 10 billion times that of the Sun.
C) Spectra of active galactic nuclei show that clouds of gas are orbiting a central object at very high speed.
D) The most luminous active galactic nuclei have huge redshifts.
D
You might also like to view...
Absolute visual magnitude is
a. the apparent magnitude of a star observed from Earth. b. the luminosity of a star observed from a distance of 1000 pc. c. the apparent magnitude of a star observed from a distance of 10 pc. d. the luminosity of a star observed from Earth. e. c and d
Pluto's density is most similar to
A) the terrestrial planets. B) the jovian planets. C) moons of the jovian planets. D) Mercury, but nor Venus, Earth, or Mars. E) Saturn, but not Jupiter, Uranus, or Neptune.
If the number of turns in a rectangular coil of wire that is rotating in a magnetic field is doubled, what happens to the induced emf, assuming all the other variables remain the same?
A) It stays the same. B) It is reduced by a factor of 4. C) It is reduced by a factor of 2. D) It is doubled. E) It is quadrupled.
Approximately how many stars does a dwarf elliptical galaxy have?
A) 1 trillion B) less than a million C) 100 billion D) less than a billion E) 10 billion