Why do almost all active galaxies occur in clusters of galaxies?
What will be an ideal response?
The conditions for feeding the active galaxy's black hole are greatly assisted by tidal interactions or even cannibalism; such collisions will be much more common in rich clusters, where the galaxies are much closer than normal.
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A mass on a spring vibrates in simple harmonic motion at a frequency of 4.0 Hz and an amplitude of 8.0 cm. If a timer is started when its displacement from equilibrium is a maximum (hence x = 8 cm when t = 0), what is the displacement of the mass when t = 3.7 s?
a. zero b. 0.025 m c. 0.049 m d. 0.080 m
Some lobes of radio galaxies are in fact moving faster than the speed of light
Indicate whether the statement is true or false
If the intensity level at distance d of one trombone is 70 dB, what is the intensity level of 76 identical trombones, all at distance d?
A) 146 dB B) 89 dB C) 5320 dB D) 76 dB E) 82 dB
One possible feedback effect of global warming that could "run away" unpredictably is
A) warming of the Pacific ocean stops the El Niño phenomenon which leads to further warming of the Pacific. B) warming leading to decreased cloud cover leading to further warming. C) ozone depletion that allows more ultraviolet to strike Earth, leading to further ozone depletion. D) melting Arctic ice leading to increased absorption of radiation leading to further warming.