Intermittent maser flare around the high mass young stellar object G353.273+0.641 I : data & overview
Intermittent maser flare around the high mass young stellar object G353.273+0.641 I : data & overview
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高质量年轻恒星物体 G353.273 0.641 I 周围的间歇性脉泽耀斑：数据
DOI：
10.1111/j.1365-2966.2011.19173.x
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发表时间：
2011
影响因子：
4.8
通讯作者：
+11 Authors
中科院分区：
文献类型：
--
作者：
Kazuhito Motogi;+11 Authors
我们已经进行了很长的基线干涉测量（VLBI）和单碟监测22 GHz的H2O脉泽发射的高质量的年轻恒星对象G353。273+ 0.641与射电天体测量的VLBI探索（VERA）和Tomakamai 11米射电望远镜。两个脉泽耀斑已经被发现，相隔近两年。频繁的VLBI监测表明，耀斑活动伴随着H_2O脉泽排列追踪到的显著激波阵面的结构变化。我们只探测到蓝移辐射，所有脉泽特征都分布在200× 200 au 2的很小区域内，尽管速度范围很宽（> 100 km s-1）。光变曲线显示出明显的间歇性变化，表明G353中的H_2O脉泽。273+ 0.641是由幕式射电喷流激发的。102年的时间尺度和10500 km s− 1的特征速度也支持这一解释。两个孤立的速度分量，C50（− 53±7 km s− 1）和C70（− 73±7 km s− 1），在耀斑阶段表现出通量加权值的同步线性加速度（− 5 km s− 1 yr− 1）。这可以转换为1.1× 10− 3 M km s− 1 yr− 1的下限动量率。特别是脉泽性质与IRAS 20126+ 4104非常相似。这证实了先前的建议，即G353。273+ 0.641是一个候选的大质量原恒星天体。在这种情况下，圆盘喷射系统的可能的极上几何形状可能适合于吸积盘的直接成像。
We have performed very long baseline interferometry (VLBI) and single-dish monitoring of 22-GHz H2O maser emission from the high-mass young stellar object G353. 273+ 0.641 with the VLBI Exploration of Radio Astrometry (VERA) and the Tomakamai 11-m radio telescope. Two maser flares have been detected, separated by almost two years. Frequent VLBI monitoring has revealed that the flare activity has been accompanied by structural change of the prominent shock front traced by H2O maser alignments. We have detected only blueshifted emission and all maser features have been distributed within a very small area of 200× 200 au2, in spite of a wide velocity range (> 100 km s− 1). The light curve shows notably intermittent variation and suggests that the H2O masers in G353. 273+ 0.641 are excited by an episodic radio jet. The time-scale of∼ 2 yr and characteristic velocity of∼ 500 km s− 1 also support this interpretation. Two isolated velocity components, C50 (− 53±7 km s− 1) and C70 (− 73±7 km s− 1), have shown synchronized linear acceleration of the flux-weighted values (∼− 5 km s− 1 yr− 1) during the flare phase. This can be converted to the lower-limit momentum rate of 1.1× 10− 3 M⊙ km s− 1 yr− 1. The maser properties are quite similar to those of IRAS 20126+ 4104 especially. This corroborates the previous suggestion that G353. 273+ 0.641 is a candidate high-mass protostellar object. The possible pole-on geometry of the disc–jet system may be suitable for direct imaging of the accretion disc in this case.