THE TRUE DURATIONS OF STARBURSTS: HUBBLE SPACE TELESCOPE OBSERVATIONS OF THREE NEARBY DWARF STARBURST GALAXIES
THE TRUE DURATIONS OF STARBURSTS: HUBBLE SPACE TELESCOPE OBSERVATIONS OF THREE NEARBY DWARF STARBURST GALAXIES
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星暴的真实持续时间：哈勃太空望远镜对附近三个矮星暴星系的观测
DOI：
10.1088/0004-637x/695/1/561
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Weisz
中科院分区：
文献类型：
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作者：
K. McQuinn;E. Skillman;J. Cannon;J. Dalcanton;A. Dolphin;D. Stark;D. Weisz
星暴的持续时间是影响星系演化的基本参数，但迄今为止，对星暴持续时间的观测限制尚未确定。在这里，我们研究了三个附近矮星系最近的恒星形成历史，以使用统一一致的方法严格量化其星暴事件的持续时间。我们发现爆发的持续时间范围为~200到~400 Myr，解决了通常通过观察得出的较短时间尺度与动态论证得出的较长时间尺度之间的紧张关系。如果这三个星暴是矮星系中星暴的典型，那么之前研究中与星暴相关的短时间尺度（3-10 Myr）最好被理解为“闪烁”事件，它们只是较大星暴的一小部分。在这个附近三个矮星的样本中，爆发不是局部事件。所有三个系统都在高恒星密度和低恒星密度区域显示出恒星形成的爆发水平。增强的恒星形成在爆发期间围绕星系移动，并覆盖了星系的大部分区域。这些大规模、持续时间长的爆发可以显着影响宿主星系的结构、动力学和化学演化，并且可以成为“超级风”的前身，将许多最近化学富集的物质从星系驱动到星系际介质中。
The 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.