More Active Galaxies and Quasars

How are AGNs and QSOs useful as natural astronomical aids?

QSOs and AGNs are such bright, yet compact, objects that they shine like cosmic searchlights; thus, they are relatively easy to detect even if they are very far away. Therefore, when we observe a distant QSO, all the material between it and us is lit up. We can search the spectra of QSOs to see if there is evidence of matter that we cannot see directly, except with the illumination of the QSO light.


This is a web preview of the "The Handy Astronomy Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App