small regions of strong radio emission. With increasing spatial resolution of radio telescopes the strong radio emission often seemed to come from a pair of lobes surrounding many of these faint star-like emission line objects.The initial method of selection was strong radio emission, and then later any object with blue or ultraviolet excess was considered a good quasar candidate. Very recent evidence from the near infrared portion of the spectrum indicates that a large fraction of quasars may in fact be brighter in the infrared than in other wavelength bands.Answering these basic questions may summarize much of the information regarding Quasar.What is the definition of a quasar? When radio telescopes were first turned on the heavens, point sources of radio waves were discovered (along with spread-out regions of emission along our Milky Way). Astronomers using ordinary visible-light telescopes turned toward these radio points and looked to see what was there. In some cases a supernova remnant was found, in others, a large star-birth region, in others a distant galaxy. But in some places where point sources of radio waves were found, no visible source other than a stellar-looking object was found (it looked like a point of a star). These objects were called the quasi-stellar radio sources or quasars for short. Later, it was found these sources could not be stars in our galaxy, but must be very far away as far as any of the distant galaxies seen. We now think these objects are the very bright centers of some distant galaxies, where some sort of energetic action is occurring, most probably due to the presence of a supermassive black hole at the center of that galaxy. (Supermassive - made up from a mass of about a billion solar masses.)What do quasars have to do with black holes? It is thought the infall of matter into the Supermassive black hole can result in very hot regions where huge energies are released, powering the quas...
