Question

How is the energy that powers radio galaxies, quasars, and other active galactic nuclei produced?

A) by nuclear fusion near a central black hole
B) by magnetic fields that trap and accelerate charged particles, which then radiate high amounts of energy
C) by matter that has been converted to pure energy being shot out as jets by a central black hole
D) by gravity, which converts potential energy of matter falling toward a central black hole into kinetic energy, which is then converted to thermal energy by collisions among the particles of matter
E) by matter-antimatter annihilation near a central black hole

Answer 1

Option (B), The energy of active galactic nuclei like quasars is mainly produced by gravity as matter falls toward a central black hole, forms a hot accretion disk, and radiates significant amounts of energy due to high temperatures and particle collisions.

Step-by-step explanation:

The energy that powers radio galaxies, quasars, and other active galactic nuclei is produced primarily by gravity, which converts the potential energy of matter falling toward a central black hole into kinetic energy. As this matter spirals closer to the black hole, it forms an accretion disk that accelerates and becomes highly compressed, heating up to temperatures of millions of degrees.

The intense thermal energy is generated by collisions among the particles of matter, resulting in the emission of vast amounts of energy. Additionally, in this energetic environment, some matter may be ejected in narrow, high-speed jets perpendicular to the accretion disk, which can extend far beyond the host galaxy and are visible in multiple wavelengths, including radio waves, light, and occasionally X-rays.