Which of the following statements about quasars is most accurate?
Show answer & explanation
Correct answer: C
Explanation
Solution: The correct answer is They are active galactic nuclei powered by supermassive black holes.
Explanation:
☛ The term quasar stands for quasi-stellar radio source.
☛ Quasars are extremely luminous active galactic nuclei (AGN) situated at the centres of distant galaxies.
☛ They are powered by supermassive black holes containing millions to billions of times the mass of the Sun.
☛ As matter falls toward the black hole, an accretion disk forms around it where intense gravitational force and friction heat the gas, releasing enormous amounts of energy across the electromagnetic spectrum.
Extra Exam-Relevant Facts:
☛ First Discovered Quasar: The first identified quasar was 3C 273, discovered in 1963 by astronomer Maarten Schmidt.
☛ Neutron Stars & Pulsars: Rapidly rotating magnetized neutron stars that emit pulses of radiation are called pulsars, whereas those with extremely intense magnetic fields are known as magnetars.
☛ Supermassive Black Hole of Milky Way: The supermassive black hole at the center of our Milky Way galaxy is known as Sagittarius A*.
Important One-Liners for Upcoming Exams:
☛ What does the acronym 'Quasar' stand for? → Quasi-stellar radio source
☛ Which was the first quasar ever identified by astronomers? → 3C 273
☛ What is the boundary around a black hole beyond which light cannot escape called? → Event Horizon
☛ What is a highly magnetized, rapidly rotating neutron star known as? → Pulsar
☛ What is the name of the supermassive black hole at the center of the Milky Way? → Sagittarius A*