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Turn, Turn, Turn

In Quasars by Brian Koberlein0 Comments

Quasars are supermassive black holes that are very far away. This means the study of quasars allow us to understand the earliest examples of active black holes, but it also means they can be difficult to observe. But for one quasar, its location behind a closer galaxy allows us to better determine its properties. In particular we now know it rotates very quickly.

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Go With the Flow

In Cosmology by Brian Koberlein9 Comments

When measuring the motion of distant galaxies, we use the Doppler effect to measure their speed relative to us.  Basically, as a galaxy moves away from us, the light from the galaxy appears more red than it actually is.  This is similar to the way the sound of a train can sound lower as it moves away from you.  Of …