Podcast
Questions and Answers
What powers the emission from an active galactic nucleus (AGN) in a quasar?
What powers the emission from an active galactic nucleus (AGN) in a quasar?
- White dwarf surrounded by a gaseous accretion disc
- Regular star surrounded by a gaseous accretion disc
- Supermassive black hole surrounded by a gaseous accretion disc (correct)
- Neutron star surrounded by a gaseous accretion disc
What is the origin of the redshifts of quasars?
What is the origin of the redshifts of quasars?
- They are caused by Doppler effect due to their motion in the universe
- They are caused by the expansion of the universe (correct)
- They are caused by the absorption of light by interstellar dust
- They are caused by the scattering of light by galactic magnetic fields
What is the significance of the term 'quasi-stellar object' (QSO) as it relates to quasars?
What is the significance of the term 'quasi-stellar object' (QSO) as it relates to quasars?
- It indicates that they have properties intermediate between stars and galaxies
- It indicates that they are similar to regular stellar objects but have different origins
- It indicates that they are not actually stars but resemble stars in visible wavelengths (correct)
- It indicates that they are actually stars with unusual characteristics
What has high-resolution imaging, particularly from the Hubble Space Telescope, revealed about the location of quasars in galaxies?
What has high-resolution imaging, particularly from the Hubble Space Telescope, revealed about the location of quasars in galaxies?
What is thought to power the emission from an active galactic nucleus (AGN) in a quasar?
What is thought to power the emission from an active galactic nucleus (AGN) in a quasar?
What are the observed properties of a quasar dependent on?
What are the observed properties of a quasar dependent on?
How many quasars have been identified with reliable spectroscopic redshifts?
How many quasars have been identified with reliable spectroscopic redshifts?
At what redshift was quasar ULAS J1342+0928 detected?
At what redshift was quasar ULAS J1342+0928 detected?
When was the light observed from quasar Pōniuāʻena emitted?
When was the light observed from quasar Pōniuāʻena emitted?
When was the peak epoch of quasar activity?
When was the peak epoch of quasar activity?
Study Notes
Quasar Properties and Origins
- The emission from an active galactic nucleus (AGN) in a quasar is thought to be powered by the accretion of material onto a supermassive black hole.
Quasar Redshifts
- The redshifts of quasars originate from the expansion of the universe, with quasars being extremely luminous objects at large cosmic distances.
Quasar Terminology
- The term 'quasi-stellar object' (QSO) refers to quasars because they appear as point-like objects, similar to stars, but have much higher luminosities.
Quasar Locations
- High-resolution imaging, particularly from the Hubble Space Telescope, has revealed that quasars are often located at the centers of galaxies.
Quasar Emission
- The emission from an active galactic nucleus (AGN) in a quasar is thought to be powered by the accretion of material onto a supermassive black hole.
Quasar Properties
- The observed properties of a quasar are dependent on the orientation of the AGN, the amount of dust and gas in the surrounding environment, and the distance of the quasar.
Quasar Identification
- Over 200,000 quasars have been identified with reliable spectroscopic redshifts.
Quasar Detection
- Quasar ULAS J1342+0928 was detected at a redshift of 7.54, making it one of the most distant quasars observed.
Quasar Light
- The light observed from quasar Pōniuāʻena was emitted around 13.4 billion years ago, when the universe was still in its early stages.
Quasar Activity
- The peak epoch of quasar activity occurred around 10-12 billion years ago, during a period of intense galaxy formation and supermassive black hole growth.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge about quasars and active galactic nuclei, extremely luminous objects powered by supermassive black holes with gaseous accretion discs. Learn about the emission of electromagnetic radiation and the enormous radiant energy of quasars.
