SEQUENTIAL STAR FORMATION IN A COMETARY GLOBULE (BRC37) OF IC1396
SEQUENTIAL STAR FORMATION IN A COMETARY GLOBULE (BRC37) OF IC1396
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DOI：
10.1088/0004-6256/135/6/2323
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发表时间：
2008-04
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影响因子：
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通讯作者：
H. Ikeda;K. Sugitani;Makoto Watanabe;N. Fukuda;M. Tamura;Y. Nakajima;A. Pickles;C. Nagashima;T. Nagayama;H. Nakaya;M. Nakano;T. Nagata
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作者：
H. Ikeda;K. Sugitani;Makoto Watanabe;N. Fukuda;M. Tamura;Y. Nakajima;A. Pickles;C. Nagashima;T. Nagayama;H. Nakaya;M. Nakano;T. Nagata
我们进行了近红外/光学观测，研究了一个明亮边缘的彗星状球状体（BRC 37）的星星形成过程，该球状体面对着一个含有IRAS源的H ii区（IC 1396）的激发星星（s），它被认为是一颗中等质量的原星星。利用无狭缝光谱仪，我们在球状体周围探测到10颗Hα发射星，其中6颗位于球状体的尖端附近，并且沿着激发星的方向排列。有证据表明，这种排列最初是朝着一颗O9.5星星排列的，但在形成时已经进化为朝着一颗更年轻的O 6星星排列。近红外线和光学测光显示，这六颗恒星中有四颗是低质量的年轻恒星天体（YSO），质量约为0.4M。它们的估计年龄为1000万年，表明它们是在IRAS源形成之前在尖端形成的。因此，很可能是连续的星星的形成已经发生沿着方向从激发星对红外天文台的来源，由于紫外线的影响，激发星星（S）。有趣的是，一颗微弱的Hα发射星星，它最接近令人兴奋的星星，似乎是一颗年轻的褐矮星，它是在尖端其他YSO形成之前由紫外线撞击形成的。
We have carried out near-IR/optical observations to examine star formation toward a bright-rimmed cometary globule (BRC37) facing the exciting star(s) of an H ii region (IC1396) containing an IRAS source, which is considered to be an intermediate-mass protostar. With slitless spectroscopy we detected ten Hα emission stars around the globule, six of which are near the tip of the globule and are aligned along the direction to the exciting stars. There is evidence that this alignment was originally toward an O9.5 star, but has evolved to align toward a younger O6 star when that formed. Near-IR and optical photometry suggests that four of these six stars are low-mass young stellar objects (YSOs) with masses of ∼0.4 M☉. Their estimated ages of ∼1 Myr indicate that they were formed at the tip in advance of the formation of the IRAS source. Therefore, it is likely that sequential star formation has been taking place along the direction from the exciting stars toward the IRAS source, due to the UV impact of the exciting star(s). Interestingly, one faint, Hα emission star, which is the closest to the exciting star(s), seems to be a young brown dwarf that was formed by the UV impact in advance of the formation of other YSOs at the tip.