Quasars

• What are quasars also known as?

  Quasi-stellar objects
• What are the characteristics of quasars?

  They are luminous, star-like sources with high redshifts
• When were quasars first discovered?

  In the 1960s
• What notable features led to the discovery of quasars?

  Strong radio emissions and high luminosities
• What is the significance of redshifts in quasars?

  They indicate the distance and age of quasars
• What are quasars classified as in terms of galactic structure?

  Active galactic nuclei
• What surrounds a supermassive black hole in a quasar?

  An accretion disc of matter

  
• What happens when matter falls into a quasar?

  It becomes active and emits radiation
• What is emitted from the poles of a quasar?

  Jets of radiation
• How much matter can fall into a quasar each year?

  The equivalent of 100 solar masses
• What is transferred to electromagnetic radiation in a quasar?

  The gravitational potential energy of infalling matter
• What types of wavelengths do quasars emit?

  All wavelengths, not just radio waves
• Why are quasars considered some of the most distant measurable objects?

  Due to their extremely large redshifts
• What does the large redshift of quasars allow astronomers to do?

  See far back to the early Universe
• What period does the observation of quasars relate to in cosmic history?

  Not long after the Big Bang