Question

An astronomer, driven by a childhood fascination with the Guinness Book of World Records, is obsessed with finding the most distant quasar ever, identified by the largest redshift. Where should she focus her search to have the best chance of discovering such a quasar? Choose from the following options:

O In the centers of nearby galaxies
O In the constellation of Sagittarius, where we see the center of the Milky Way
O Right next to 3C273, the first quasar that was understood
O In or near a distant cluster of galaxies that can act like a gravitational lens
O There is simply no way she can improve her chances; such discoveries are completely random.

Answer 1

To discover the most distant quasar, the astronomer should search near galaxy clusters that can gravitate and magnify the light from quasars, enhancing visibility and aiding in the identification of quasars with large redshifts.

Step-by-step explanation:

The astronomer seeking the most distant quasar should focus her search on or near a distant cluster of galaxies that can act like a gravitational lens. Clusters of galaxies can magnify the light from distant quasars, making it easier to detect them. Because quasars are extremely luminous and found in the centers of both spiral and elliptical galaxies, identifying quasars with the largest redshifts is indicative of finding the most distant ones. The gravitational lensing effect caused by massive galaxy clusters can help in observing quasars that would otherwise be too faint to detect, thereby increasing the chances of discovering a record-breaking distant quasar.

Quasars are brilliant centers of galaxies that emit an enormous amount of energy. They can be located at great distances, allowing astronomers to probe the universe billions of light-years away and therefore billions of years in the past.

Observations with the Hubble Space Telescope have shown that quasars are found at the centers of galaxies, and they can outshine their entire galaxies by factors of 10 to 100 or more. By searching for quasars in or near distant clusters of galaxies that can act like gravitational lenses, the astronomer increases her chances of discovering the most distant quasar with the largest redshift.