The bubble G15.684-0.29 has a radius of 15.7 pc. Its large size indicates that it may have enough time to trigger star formation. We identify 39 dense cold clumps around the bubble from the Hi-GAL survey. All of them satisfy the criteria for forming massive stars, and most of them lie in the bubble shell. We identify 19 molecular clumps around the bubble from the 12 CO(3–2) survey, all of which are gravitationally bound. We found 9 Class I YSOs, 28 Class II YSOs, and 12 transition disks (TDs) around the bubble. For those young stellar objects (YSOs) located within the bubble boundary, 6 of 7 Class I YSOs lie in the shell, 15 of 22 Class II YSOs lie inside the bubble, and 3 of 5 TDs lie inside the bubble. The dynamical age of G15.684-0.29 in a turbulent medium is ∼4 Myr, which is much greater than the shell fragmentation time, ∼0.82–1.74 Myr. We suggest that triggered star formation may be ongoing in the shell of the bubble, and the collect and collapse model may work h...

中文翻译：

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G15.684-0.29：最大的银河红外气泡之一，显示出引发恒星形成的强烈证据

气泡G15.684-0.29的半径为15.7 pc。它的大尺寸表明它可能有足够的时间触发恒星形成。根据Hi-GAL调查，我们在气泡周围发现了39个密集的冷块。它们全部满足形成大质量恒星的标准，并且大多数都位于气泡壳中。我们从12 CO（3–2）调查中识别出气泡周围的19个分子团块，所有这些团块都是受重力约束的。我们在气泡周围发现了9个I类YSO，28个II类YSO和12个过渡盘（TD）。对于位于气泡边界内的年轻恒星物体（YSO），在外壳中有7个I类YSO中的6个，在气泡内部有22个II类YSO中的15个，在气泡内部有5个TD中的3个。在湍流介质中，G15.684-0.29的动力学年龄为〜4 Myr，比壳碎裂时间〜0.82-1.74 Myr大得多。