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type 2 Seyfert galaxy
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The small spiral galaxy NGC 7742, a Type 2 Seyfert galaxy, as seen by the Hubble Space Telescope.
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type 2 Seyfert galaxy

astronomy
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The small spiral galaxy NGC 7742, a Type 2 Seyfert galaxy, as seen by the Hubble Space Telescope.
The small spiral galaxy NGC 7742, a Type 2 Seyfert galaxy, as seen by the Hubble Space Telescope.

A Type 2 Seyfert galaxy is a type of active galactic nucleus (AGN) that has a bright, compact core. These galaxies were first identified by astronomer Carl K. Seyfert in 1944. While appearing normal in regular images, Seyfert galaxies are powerful sources of infrared radiation, radio energy, and X-rays.1

Type 2 Seyferts are characterized by strong emission lines in their spectra, indicating gas expanding at speeds less than 1,000 km/sec. This activity is believed to be powered by a supermassive black hole at the galaxy's center, which accretes matter. This process heats the matter, causing it to outshine the rest of the galaxy. About 1% of spiral galaxies are thought to exhibit Seyfert properties.123

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4 Britannica Sources
  1. active galactic nucleus
  2. Seyfert galaxy
  3. Seyfert galaxy
  4. supermassive black hole

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