In what ways can we distinguish between a human and bot behavior?

A) Name two ways that astronomers use to distinguish active galaxies from normal ones. (b) Why do active galax?

• a) Name two ways that astronomers use to distinguish active galaxies from normal ones. (b) Why do active galaxies emit large amount of radio & infrared but less visible light?

• Answer:

  Since active galaxy covers a broad range of observed phenomena, you have many choices. Since your part b question indicates you are interested in radio active galaxies. Number one would be they are a source of a continuous radio region emissions which are a result of synchrotron radiation from a relativistic jet. Number two - High infrared emission due to absorption of energy by obscuring dust which is then re-emitted as thermal radiation. Yet another observation method is the use of x-ray spectra to analyze the structure of the accretion disk by using the relativistically broadened iron lines around 6.4 KeV. Part b). We believe active galaxies are the result of a central black hole in the galactic nucleus which has an accretion disk. The accretion disk emits various forms of energy...including strong x-rays... as in falling matter collides and is heated as it accelerates and spirals inward towards the black hole. We also sometimes observe polar relativistic jets spewing from the center. The jets are the source of continuous radio wave spectrum. There is less visible light because the central black hole is usually obscured by dust/ gas that is opaque to visible light.