Nuclear characteristics of active galaxies
A typical active galaxy core has the following characteristics:
1. High brightness
The optical luminosity is not much different from that of ordinary galaxies. The radio luminosity is about 20 ~ 2 × 106 times that of ordinary galaxies, while quasars are up to 6 × 106 times.
2. Rapid optical change
The light cycle is generally from a few days to a year or so, and even the active light system's nuclear light cycle is only a few hours.
3. Non-thermal continuous radiation, highly polarized radiation
The radiation of normal galaxies is black body radiation, the maximum value is in the optical band, and the nuclear spectrum of the active galaxy is complex, and the maximum value is in the far infrared band (non
Heat radiation).
4. The radio wave band has a special shape
There are often jets, bright nuclei, and irregular patterns observed by people in the radio wave band.
5. Strong launch line
The emission line originates from the ionization of the high-energy radiation in the central area to the surrounding environment, and usually appears as a metal line in the spectrum.
6. Its host galaxy is bleak