Radio Imaging of the NGC 1333 IRAS 4A Region: Envelope, Disks, and Outflows of a Protostellar Binary System
Radio Imaging of the NGC 1333 IRAS 4A Region: Envelope, Disks, and Outflows of a Protostellar Binary System
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NGC 1333 IRAS 4A 区域的射电成像：原恒星双星系统的包层、圆盘和流出物
DOI：
10.1093/pasj/63.6.1281
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发表时间：
2011
影响因子：
2.3
通讯作者：
Geumsook Park
中科院分区：
文献类型：
--
作者：
Minho Choi;Miju Kang;K. Tatematsu;Jeong;Geumsook Park
NGC 1333 IRAS 4A原双星在1.3 cm和6.9 mm连续谱线以及氨和SiO谱线中观测到，角分辨率约为0.4弧秒。连续图显示了两颗原恒星A1和A2的星周结构。A1星系比A2星系更亮，质量也更大。包括致密气体和原恒星在内的质量比约为6。星周盘和流出物的特性表明A1可能比A2年轻。A2的东北喷流的偏转部分在SiO线上是明亮的，最亮的峰与偏转点之间的距离表明，SiO的增强大约在与致密核碰撞后100年左右。氨图显示了一个小结构，似乎是阻塞核心的一部分。通过比较SiO、氨、甲醛和HCN线的干涉图，研究了流出物的性质。它们的整体结构非常一致，这表明这些物种是由相同的机制激发的。然而，强度分布表明SiO在化学上是独特的。SiO可能与主喷流直接相关，而其他物种可能在追踪夹带的环境气体。
The NGC 1333 IRAS 4A protobinary was observed in the 1.3 cm and 6.9 mm continuum and the ammonia and SiO lines, with an angular resolution of about 0.4 arcseconds. The continuum maps show the circumstellar structures of the two protostars, A1 and A2. The A1 system is brighter and more massive than the A2 system. The ratio of mass, including dense gas and protostar, is about 6. The properties of the circumstellar disks and outflows suggest that A1 may be younger than A2. The deflected part of the northeastern jet of A2 is bright in the SiO line, and the distance between the brightest peak and deflection point suggests that the enhancement of SiO takes about 100 yr after the collision with a dense core. The ammonia maps show a small structure that seems to be a part of the obstructing core. The outflow properties were studied by comparing interferometric maps of SiO, ammonia, formaldehyde, and HCN lines. Their overall structures agree well, suggesting that these species are excited by the same mechanism. However, the intensity distributions show that SiO is chemically unique. SiO may be directly linked to the primary jet while the other species may be tracing the entrained ambient gas.