Starburst galaxy

A starburst galaxy ( starburst engl. Approximately "Star outbreak " ) is a galaxy, far more new stars in, as is typical for a galaxy of this size.

The demarcation of normal galaxies is not sharply defined. Usually, called starburst galaxies only galaxies whose star formation rate is so high that it can not be maintained over billions of years from the existing gas supply. The term is sometimes also applied Starburst to subareas of galaxies with spatially restricted active star formation. He loses his sense on the smaller scale of star-forming regions, as they are often in normal spiral galaxies.

The young stars of starbursts emit strongly in the ultraviolet region of the electromagnetic radiation and ionize large parts of the interstellar medium of the galaxy. Many starburst galaxies contain so much dust that most of the luminosity of their young stars is absorbed by dust and over 90 % of their total energy is re-radiated in the far infrared. Starbursts of various properties were therefore in sky surveys in the ultraviolet (eg by Benjamin Markarian and employees in the 1960s ) or in the far infrared (especially IRAS ) discovered. Many infrared galaxies are starburst galaxies. A well-known example is Messier 82

Interaction and merging of galaxies can stimulate starbursts, as well as gas flows along the bars of barred spiral galaxies. Studies of starburst galaxies to deal inter alia with the mass distribution of newly formed stars, the resulting in starbursts compact massive star clusters and with the emerging radiation and stellar winds feedback on the interstellar and intergalactic medium. Due to the stellar winds and supernova explosions in a starburst galaxy a part of their interstellar medium can be heated so much that it can leave it in a super wind.