Question

Rank the features of an active galaxy in order of their apparent size, largest first: accretion disk, jet, radio lobe, supermassive black hole.

Answer 1

In descending order of size for the features of an active galaxy, radio lobes are the largest, followed by jets, the accretion disk, and finally the supermassive black hole being the smallest.

Step-by-step explanation:

When ranking the features of an active galaxy according to their apparent size, largest first, we find the following order:

1. Radio lobes are the largest features, often extending far beyond the starry edges of the galaxy, sometimes spreading over hundreds of thousands of light-years across.
2. Jets, which are streams of material propelled at speeds close to the speed of light, can extend several thousands to tens of thousands of light-years from the galactic nucleus.
3. The accretion disk is much smaller in comparison, with its size typically less than 1 light-year across; it is a ring of dust and gas that heats up and outshines much of the galaxy.
4. The supermassive black hole itself is the smallest feature, with its size being a mere fraction of a light-year.

This hierarchy in sizes is crucial for understanding the structure of an active galaxy, such as the ones depicted in observations by the Hubble Space Telescope and the Very Large Array.