Kristen B. W. McQuinn et al. 2009 ApJ 695 561 doi:10.1088/0004-637X/695/1/561
Kristen B. W. McQuinn1, Evan D. Skillman1, John M. Cannon2, Julianne J. Dalcanton3, Andrew Dolphin4, David Stark1 and Daniel Weisz1
Show affiliationsThe duration of a starburst is a fundamental parameter affecting the evolution of galaxies yet, to date, observational constraints on the durations of starbursts are not well established. Here we study the recent star formation histories of three nearby dwarf galaxies to rigorously quantify the duration of their starburst events using a uniform and consistent approach. We find that the bursts range from ~200 to ~400 Myr in duration resolving the tension between the shorter timescales often derived observationally with the longer timescales derived from dynamical arguments. If these three starbursts are typical of starbursts in dwarf galaxies, then the short timescales (3-10 Myr) associated with starbursts in previous studies are best understood as "flickering" events which are simply small components of the larger starburst. In this sample of three nearby dwarfs, the bursts are not localized events. All three systems show bursting levels of star formation in regions of both high and low stellar density. The enhanced star formation moves around the galaxy during the bursts and covers a large fraction of the area of the galaxy. These massive, long-duration bursts can significantly affect the structure, dynamics, and chemical evolution of the host galaxy and can be the progenitors of "superwinds" that drive much of the recently chemically enriched material from the galaxy into the intergalactic medium.
galaxies: dwarf; galaxies: evolution; galaxies: individual (NGC 4163, NGC 4068, IC 4662); galaxies: starburst
Issue 1 (2009 April 10)
Received 2008 July 15, accepted for publication 2009 January 13
Published 2009 March 31
Kristen B. W. McQuinn et al. 2009 ApJ 695 561