Outline the core engine responsible for the immense power output of a quasar, stating the type of object at the center and where it is situated within its host environment.
An actively radiating quasar is observed at a distance of 9.50×108 light-years9.50 \times 10^8\text{ light-years}9.50×108 light-years with a measured redshift of z=0.0680z = 0.0680z=0.0680. Use these observational data to estimate the age of the Universe in seconds. (Take 1 light-year=9.46×1015 m1\text{ light-year} = 9.46 \times 10^{15}\text{ m}1 light-year=9.46×1015 m and the speed of light in a vacuum c=3.00×108 m s−1c = 3.00 \times 10^8\text{ m s}^{-1}c=3.00×108 m s−1.)
A highly active quasar is believed to have a total luminosity (power output) approximately 250025002500 times that of a typical spiral galaxy. By applying the inverse-square law, estimate how many times further away this quasar could be detected compared to the spiral galaxy, assuming both require the same minimum detectable brightness (received intensity) at Earth.
15 exam-style questions on AQA A Level Physics Cosmology (A-level only), covering Doppler effect (A-level only), Hubble's law (A-level only), Quasars (A-level only), and Detection of exoplanets (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.