What are Quasars?

Quasar

QUASARS (Quasi-Stellar Radio Source) [QSR]

  • Appear like stars
  • Emits strong radio signal
  • Distant active¬†nuclei¬†of galaxies
  • A compact region in the center of a massive galaxy surrounding its central supermassive black hole
  • Traveling away from Earth at tremendous speeds (largest Doppler red shifts known)
  • First discovered 20 years ago (3C273) by interaction of optical and radio astronomy
  • In 1963, Maarteen Schmid discovered a quasar with a 16% Doppler red shift (~3 billion light years away)
  • Since then, more than 1,500 quasars discovered with red shifts up to 473%
  • Provide information of the early phases of the Universe
  • Have been found in a cluster of galaxies (“host galaxies”)

Hubble’s Law: large redshift means large velocities of recession = great distances