论文标题
麦哲伦云的同步舞蹈的恒星形成历史
The synchronised dance of the Magellanic Clouds' star formation history
论文作者
论文摘要
我们使用SMASH调查来获得前所未有的深度光度法，直至到达小麦芽岩（SMC）的颜色磁性图（CMD）中最古老的主序列转换，并使用CMD拟合技术定量得出其星形形成历史（SFH）。我们在最后3.5 Gyr中确定了五个独特的恒星形成峰值，$ \ sim $ 3，$ \ sim $ 2，$ \ sim $ 1.1，$ \ sim $ 0.45 Gyr of，目前是一个。我们将它们与大型麦哲伦云（LMC）的SFH进行了比较，发现了明确的同步性，两个星系在过去的$ \ sim $ 3.5 Gyr中都显示出相似的增强恒星形成的时期。其SFH之间的并行性表明，MC之间的潮汐相互作用在其演变中反复发挥了重要作用，至少最后一个$ \ sim $ 3.5 GYR，潮汐缩小了SMC并塑造了LMC的螺旋臂。我们首次展示了SMC-LMC在最近的SFH中相关联的SFH，其中恒星形成的增强位于LMC的北部螺旋臂中，并在全球范围内穿过SMC。这些新颖的发现不仅应用于限制MC的轨道病史，还应在模拟中处理恒星形成。
We use the SMASH survey to obtain unprecedented deep photometry reaching down to the oldest main sequence turn-offs in the colour-magnitude diagrams (CMDs) of the Small Magellanic Cloud (SMC) and quantitatively derive its star formation history (SFH) using CMD fitting techniques. We identify five distinctive peaks of star formation in the last 3.5 Gyr, at $\sim $3, $\sim$2, $\sim$1.1, $\sim $0.45 Gyr ago, and one presently. We compare these to the SFH of the Large Magellanic Cloud (LMC) finding unequivocal synchronicity, with both galaxies displaying similar periods of enhanced star formation over the past $\sim$3.5 Gyr. The parallelism between their SFHs indicates that tidal interactions between the MCs have recurrently played an important role in their evolution for at least the last $\sim$3.5 Gyr, tidally truncating the SMC and shaping the LMC's spiral arm. We show, for the first time, an SMC-LMC correlated SFH at recent times in which enhancements of star formation are localised in the northern spiral arm of the LMC, and globally across the SMC. These novel findings should be used to constrain not only the orbital history of the MCs but also how star formation should be treated in simulations.
