Starburst Galaxies: Structures & Vocabulary

A starburst galaxy is forming stars at an unusually high rate compared with its long-term average and available gas reservoir. Starbursts are intense but temporary because they consume, heat, or expel gas on timescales much shorter than a galaxy's age.

Mergers, tidal interactions, bars, or gas inflows compress molecular gas and raise the fraction dense enough to form stars. Stellar winds, radiation, and supernovae then inject energy and momentum, eventually regulating or terminating the burst.

Strong infrared luminosity, bright emission lines, abundant young clusters, radio supernova signatures, and galactic outflows identify active starbursts. Many distant galaxies at the peak era of cosmic star formation show elevated star-formation rates.

Starbursts often contain dense molecular gas, luminous young clusters, dust-obscured regions, supernovae, and large-scale winds. Nuclear and disk-wide bursts can have different triggers.