Infrared galaxy
An infrared galaxy is a galaxy that emits more energy in the infrared range of the electromagnetic spectrum than at all other wavelengths combined.
The luminosity in infrared can be more than a hundred times the luminosity in visible light. Energy sources are numerous young stars in starbursts and, especially in the case of the most luminous objects, matter incidence on a black hole in an active galactic core .
Categories
Infrared galaxies are classified according to their luminosity in the wavelength range 8 to 1000 µm:
| category | Luminosity in units of the sun |
abbreviation |
|---|---|---|
| extremely bright | > 10 14 L ☉ | ELIRG (Extremely-Luminous InfraRed Galaxies) |
| hyper luminous | > 10 13 L ☉ | HLIRG (Hyper-Luminous InfraRed Galaxies) |
| ultra luminous | > 10 12 L ☉ | ULIRG (Ultra-Luminous InfraRed Galaxies) |
| bright | > 10 11 L ☉ | LIRG (Luminous InfraRed Galaxies) |
observation
Infrared galaxies in the near universe have been discovered in large numbers by IRAS . The most famous infrared galaxies include Messier 82 and Arp 220 . Since the 1990s, infrared galaxies in the early universe have also been known from recordings in the mid-infrared and in the sub-mm range.
With the Wide-Field Infrared Survey Explorer , distant, extremely luminous infrared galaxies such as WISE J224607.57-052635.0 were discovered in 2015 . Their extreme luminosity of up to over 300 trillion solar luminosities (> 3 · 10 14 L führte ) led to the new category ELIRG .
literature
- DB Sanders, IF Mirabel: Luminous Infrared Galaxies . In: Annual Review of Astronomy and Astrophysics , 34, 1996, p. 749.
- Andreas Müller: ULIRG . In: Astro-Lexikon, Wissenschaft-online.de, 2007.
Individual evidence
- ↑ NASA: NASA's WISE Spacecraft Discovers Most Luminous Galaxy in Universe . May 21, 2015. Retrieved May 25, 2015.
- ↑ Chao-Wei Tsai et al .: The Most Luminous Galaxies Discovered by WISE . In: arXiv . April 8, 2015. arxiv : 1410.1751v2 .