论文标题
高质量恒星形成区域DR21（OH）中I类甲醇masers的长期变异性
Long-term variability of Class I methanol masers in the high mass star forming region DR21(OH)
论文作者
论文摘要
高质量恒星在星际培养基中起着重要作用，但对于它们的形成仍有许多众所周知。 I类甲醇果酱可能是高质量星形成的早期阶段的独特示踪剂，对此类簇的更好理解将使它们被用作更有效的高质量星形成过程的探针。我们对44 GHz的I类甲醇masers的长期变异性介绍了对高质量恒星形成区域DR21（OH）的长期变异性。我们将2017年至2012年进行的观察结果与文献中的2001年数据进行了比较。在2017年的数据中总共发现了57个MASER斑点，中心速度在-8.65 km/s至+2.56 km/s之间。将泥石装在一个西部和一个东叶中，每个叶中有两个弧形，看起来像弓箭，与以前的观察一致。总体趋势是从2001年到2012年的强度增加，并且从2012年到2017年的趋势下降。在西部叶的内弧中，可变性比外弧内的弧度更为普遍。我们推测这可能是发作增积的结果，其中后来的积聚事件导致了材料的弹出，其冲击在2001年后的某个时间点达到了内部弧。我们得出结论，I类甲醇蛋白酶在长时间尺度上是可变的（5 - 10年的阶段）。
High mass stars play an important role in the Interstellar Medium, but much remains to be known about their formation. Class I methanol masers may be unique tracers of an early stage of high mass star formation, and a better understanding of such masers will allow them to be used as more effective probes of the high mass star forming process. We present an investigation of the long-term variability of Class I methanol masers at 44 GHz toward the high mass star forming region DR21(OH). We compare observations taken in 2017 to 2012 and also to 2001 data from the literature. A total of 57 maser spots were found in the 2017 data, with center velocities ranging between -8.65 km/s to +2.56 km/s. The masers are arranged in a western and an eastern lobe with two arcs in each lobe that look like bowshocks, consistent with previous observations. The general trend is an increase in intensity from 2001 to 2012, and a decrease from 2012 to 2017. Variability appears to be more prevalent in the inner arc of the western lobe than in the outer arc. We speculate that this may be a consequence of episodic accretion, in which a later accretion event has resulted in ejection of material whose shock reached the inner arc at some point in time after 2001. We conclude that class I methanol masers are variable on long timescales (of the order of 5-10 years).
