Answer:
The Most Famous Astronomers of All Time. Karl Tate, SPACE.com. ...
Claudius Ptolemy. Bartolomeu Velho, Public Domain. ...
Nicolaus Copernicus. Public Domain. ...
Johannes Kepler. NASA Goddard Space Flight Center Sun-Earth Day. ...
Galileo Galilei. NASA
They almost entirely reside within galaxies because quasars are a subset of blackholes with a large and fast enough accretion disk to generate a beam of interstellar material perpendicular to itself. This typically only occurs in the largest black holes at the center of galaxies (supermassive blackholes) or at least stellar black holes---which still occur within galaxies because the material is necessary to form them.
A
More concentrated means more collisions per unit volume, and as the volume stays the same and only concentration changes, the there are more collisions
A joule is a unit of energy.
Both equinoxes ... September 21 and March 21.
